<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2024 Workiva-->
<!--r:61767a76-2f9f-45a2-a0f7-45326d8476e1,g:cf31f2fa-d3cc-4bbf-92ff-772af258739d-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://enphase.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY" xlink:type="simple" xlink:href="enph-20240630.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://enphase.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_ea312ab5-41ed-4dea-8604-45fa3c28b448" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_f78d6120-6511-407b-b7eb-f2640cea7fec" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_ea312ab5-41ed-4dea-8604-45fa3c28b448" xlink:to="loc_us-gaap_StatementTable_f78d6120-6511-407b-b7eb-f2640cea7fec" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_db22cfee-badb-4985-8756-491854dfd6cf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_f78d6120-6511-407b-b7eb-f2640cea7fec" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_db22cfee-badb-4985-8756-491854dfd6cf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_db22cfee-badb-4985-8756-491854dfd6cf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_db22cfee-badb-4985-8756-491854dfd6cf" xlink:to="loc_us-gaap_EquityComponentDomain_db22cfee-badb-4985-8756-491854dfd6cf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_d64e86c7-0f47-4709-b823-06464c645d6a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_db22cfee-badb-4985-8756-491854dfd6cf" xlink:to="loc_us-gaap_EquityComponentDomain_d64e86c7-0f47-4709-b823-06464c645d6a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockIncludingAdditionalPaidInCapitalMember_8c5b8797-7d5c-4793-af6b-35160506569d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockIncludingAdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_d64e86c7-0f47-4709-b823-06464c645d6a" xlink:to="loc_us-gaap_CommonStockIncludingAdditionalPaidInCapitalMember_8c5b8797-7d5c-4793-af6b-35160506569d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_f8179a2f-1fdf-48a6-8e0f-60b96b672b9e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_d64e86c7-0f47-4709-b823-06464c645d6a" xlink:to="loc_us-gaap_TreasuryStockCommonMember_f8179a2f-1fdf-48a6-8e0f-60b96b672b9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_b401447b-346a-4065-83e5-0757fe7f29f4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_d64e86c7-0f47-4709-b823-06464c645d6a" xlink:to="loc_us-gaap_RetainedEarningsMember_b401447b-346a-4065-83e5-0757fe7f29f4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_5b91b906-48a8-4a92-afc9-58e36ed7121c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_d64e86c7-0f47-4709-b823-06464c645d6a" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_5b91b906-48a8-4a92-afc9-58e36ed7121c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_4f7885b6-9b9d-4b89-8f5d-d5d302e0193e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_ea312ab5-41ed-4dea-8604-45fa3c28b448" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_4f7885b6-9b9d-4b89-8f5d-d5d302e0193e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_4c452b35-1cd2-41d0-8fec-2d923fad92e4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_4f7885b6-9b9d-4b89-8f5d-d5d302e0193e" xlink:to="loc_us-gaap_StockholdersEquity_4c452b35-1cd2-41d0-8fec-2d923fad92e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_b1007896-77c7-45f4-ad8f-bbdac8ee3582" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_4f7885b6-9b9d-4b89-8f5d-d5d302e0193e" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_b1007896-77c7-45f4-ad8f-bbdac8ee3582" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_fe549052-6112-4b70-be8d-dcba25b9cad1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_4f7885b6-9b9d-4b89-8f5d-d5d302e0193e" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_fe549052-6112-4b70-be8d-dcba25b9cad1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_07aba70e-5451-41c1-aaa8-262fcfc39030" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_4f7885b6-9b9d-4b89-8f5d-d5d302e0193e" xlink:to="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_07aba70e-5451-41c1-aaa8-262fcfc39030" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_5d21768d-7b9f-437e-a78c-2940e6309156" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_4f7885b6-9b9d-4b89-8f5d-d5d302e0193e" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_5d21768d-7b9f-437e-a78c-2940e6309156" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_8acd406d-f4e2-4e79-af43-e5dc125780c6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_4f7885b6-9b9d-4b89-8f5d-d5d302e0193e" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_8acd406d-f4e2-4e79-af43-e5dc125780c6" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_e5c1ea6a-37f1-40e1-8d17-9db6820f1393" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_4f7885b6-9b9d-4b89-8f5d-d5d302e0193e" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_e5c1ea6a-37f1-40e1-8d17-9db6820f1393" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_753f008f-88d7-48f1-a532-c8f5a52c3693" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_4f7885b6-9b9d-4b89-8f5d-d5d302e0193e" xlink:to="loc_us-gaap_NetIncomeLoss_753f008f-88d7-48f1-a532-c8f5a52c3693" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax_678b2bbc-f0a3-4af9-a7c6-f8cc8d7eb23f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_4f7885b6-9b9d-4b89-8f5d-d5d302e0193e" xlink:to="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax_678b2bbc-f0a3-4af9-a7c6-f8cc8d7eb23f" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_fb4ee2ed-71fd-467a-8a74-bd2f8b8927b2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_4f7885b6-9b9d-4b89-8f5d-d5d302e0193e" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_fb4ee2ed-71fd-467a-8a74-bd2f8b8927b2" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_513d8f6a-e5a7-472f-82b8-c79d0c225c78" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/REVENUERECOGNITIONSummaryofDisaggregatedRevenuebyPrimaryGeographicalMarketandTimingofRevenueRecognitionDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#REVENUERECOGNITIONSummaryofDisaggregatedRevenuebyPrimaryGeographicalMarketandTimingofRevenueRecognitionDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/REVENUERECOGNITIONSummaryofDisaggregatedRevenuebyPrimaryGeographicalMarketandTimingofRevenueRecognitionDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_3e5505fa-8b3b-4531-a8cf-2530528b9401" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_d9fc2bfa-521a-489d-ac8d-8c51fe40b2bb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_3e5505fa-8b3b-4531-a8cf-2530528b9401" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_d9fc2bfa-521a-489d-ac8d-8c51fe40b2bb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_f7ed020f-0228-495b-be37-8f87a79d92cc" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_d9fc2bfa-521a-489d-ac8d-8c51fe40b2bb" xlink:to="loc_srt_StatementGeographicalAxis_f7ed020f-0228-495b-be37-8f87a79d92cc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_f7ed020f-0228-495b-be37-8f87a79d92cc_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_f7ed020f-0228-495b-be37-8f87a79d92cc" xlink:to="loc_srt_SegmentGeographicalDomain_f7ed020f-0228-495b-be37-8f87a79d92cc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_0ee13adf-5329-46e6-b446-81bd4bf962bb" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_f7ed020f-0228-495b-be37-8f87a79d92cc" xlink:to="loc_srt_SegmentGeographicalDomain_0ee13adf-5329-46e6-b446-81bd4bf962bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_7ad23e4f-33d2-4736-98ab-e046af7e28a9" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_0ee13adf-5329-46e6-b446-81bd4bf962bb" xlink:to="loc_country_US_7ad23e4f-33d2-4736-98ab-e046af7e28a9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_InternationalMember_c5ea1fcb-4bf3-45bd-888c-f5a87d3fb9d2" xlink:href="enph-20240630.xsd#enph_InternationalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_0ee13adf-5329-46e6-b446-81bd4bf962bb" xlink:to="loc_enph_InternationalMember_c5ea1fcb-4bf3-45bd-888c-f5a87d3fb9d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_9650fded-39c4-4fab-a595-260be3d242f1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TimingOfTransferOfGoodOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_d9fc2bfa-521a-489d-ac8d-8c51fe40b2bb" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_9650fded-39c4-4fab-a595-260be3d242f1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_9650fded-39c4-4fab-a595-260be3d242f1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_9650fded-39c4-4fab-a595-260be3d242f1" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_9650fded-39c4-4fab-a595-260be3d242f1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_180cc472-d5d0-4523-bd06-3b51fc2f11d5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_9650fded-39c4-4fab-a595-260be3d242f1" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_180cc472-d5d0-4523-bd06-3b51fc2f11d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransferredAtPointInTimeMember_2ec59ece-cd34-4e10-99a1-3628cac0c215" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransferredAtPointInTimeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_180cc472-d5d0-4523-bd06-3b51fc2f11d5" xlink:to="loc_us-gaap_TransferredAtPointInTimeMember_2ec59ece-cd34-4e10-99a1-3628cac0c215" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransferredOverTimeMember_325785fc-e51a-4c2e-b39c-7ddb1055e407" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransferredOverTimeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_180cc472-d5d0-4523-bd06-3b51fc2f11d5" xlink:to="loc_us-gaap_TransferredOverTimeMember_325785fc-e51a-4c2e-b39c-7ddb1055e407" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_62873a07-3c07-4ee2-8a51-b26e18e5e167" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_3e5505fa-8b3b-4531-a8cf-2530528b9401" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_62873a07-3c07-4ee2-8a51-b26e18e5e167" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/REVENUERECOGNITIONSummaryofEstimatedRevenueExpectedtobeRecognizedinFuturePeriodsDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#REVENUERECOGNITIONSummaryofEstimatedRevenueExpectedtobeRecognizedinFuturePeriodsDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/REVENUERECOGNITIONSummaryofEstimatedRevenueExpectedtobeRecognizedinFuturePeriodsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_05c7fce1-fb03-46b8-aabd-6687abb73cbd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_1e7f60ea-1355-47c8-9a57-2a922f516896" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_05c7fce1-fb03-46b8-aabd-6687abb73cbd" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_1e7f60ea-1355-47c8-9a57-2a922f516896" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_d6d10e26-fd9e-424d-929c-c55a2e91556a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_1e7f60ea-1355-47c8-9a57-2a922f516896" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_d6d10e26-fd9e-424d-929c-c55a2e91556a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_7c08aa98-1583-4a1e-bd44-5531cb0e295a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_05c7fce1-fb03-46b8-aabd-6687abb73cbd" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_7c08aa98-1583-4a1e-bd44-5531cb0e295a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_67e1d1df-4d89-433c-82f0-349f9bf3226c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_05c7fce1-fb03-46b8-aabd-6687abb73cbd" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_67e1d1df-4d89-433c-82f0-349f9bf3226c" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/REVENUERECOGNITIONSummaryofEstimatedRevenueExpectedtobeRecognizedinFuturePeriodsDetails_1" xlink:type="simple" xlink:href="enph-20240630.xsd#REVENUERECOGNITIONSummaryofEstimatedRevenueExpectedtobeRecognizedinFuturePeriodsDetails_1"/>
  <link:definitionLink xlink:role="http://enphase.com/role/REVENUERECOGNITIONSummaryofEstimatedRevenueExpectedtobeRecognizedinFuturePeriodsDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_05c7fce1-fb03-46b8-aabd-6687abb73cbd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_1e7f60ea-1355-47c8-9a57-2a922f516896" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_05c7fce1-fb03-46b8-aabd-6687abb73cbd" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_1e7f60ea-1355-47c8-9a57-2a922f516896" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_7c08aa98-1583-4a1e-bd44-5531cb0e295a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_05c7fce1-fb03-46b8-aabd-6687abb73cbd" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_7c08aa98-1583-4a1e-bd44-5531cb0e295a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_67e1d1df-4d89-433c-82f0-349f9bf3226c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_05c7fce1-fb03-46b8-aabd-6687abb73cbd" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_67e1d1df-4d89-433c-82f0-349f9bf3226c" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/GOODWILLANDINTANGIBLEASSETSScheduleofAcquiredIntangibleAssetsDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#GOODWILLANDINTANGIBLEASSETSScheduleofAcquiredIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/GOODWILLANDINTANGIBLEASSETSScheduleofAcquiredIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_09ae8e0d-2154-407c-8f1c-23ec8091dbf1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_ef30d003-b4ad-422f-b83d-f5beb39d6908" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_09ae8e0d-2154-407c-8f1c-23ec8091dbf1" xlink:to="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_ef30d003-b4ad-422f-b83d-f5beb39d6908" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_520f8164-3a2b-47f9-a92f-7d8bee9111ce" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_ef30d003-b4ad-422f-b83d-f5beb39d6908" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_520f8164-3a2b-47f9-a92f-7d8bee9111ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_520f8164-3a2b-47f9-a92f-7d8bee9111ce_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_520f8164-3a2b-47f9-a92f-7d8bee9111ce" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_520f8164-3a2b-47f9-a92f-7d8bee9111ce_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_519fa52f-2abe-4c80-b054-6b23092537cb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_520f8164-3a2b-47f9-a92f-7d8bee9111ce" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_519fa52f-2abe-4c80-b054-6b23092537cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntellectualPropertyMember_2b260242-9d00-4079-9a77-e29c49d17572" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IntellectualPropertyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_519fa52f-2abe-4c80-b054-6b23092537cb" xlink:to="loc_us-gaap_IntellectualPropertyMember_2b260242-9d00-4079-9a77-e29c49d17572" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_338708c5-df33-4094-a93d-aaad5438d882" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_519fa52f-2abe-4c80-b054-6b23092537cb" xlink:to="loc_us-gaap_CustomerRelationshipsMember_338708c5-df33-4094-a93d-aaad5438d882" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_73e4d88d-a91c-4306-a96c-8d86ccdc0802" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_519fa52f-2abe-4c80-b054-6b23092537cb" xlink:to="loc_us-gaap_TradeNamesMember_73e4d88d-a91c-4306-a96c-8d86ccdc0802" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract_891ebd57-83b9-45a3-8b3e-af6221bcdae1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_09ae8e0d-2154-407c-8f1c-23ec8091dbf1" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract_891ebd57-83b9-45a3-8b3e-af6221bcdae1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_71c0736c-899c-4e40-9678-b07f7a43a781" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsNetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract_891ebd57-83b9-45a3-8b3e-af6221bcdae1" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_71c0736c-899c-4e40-9678-b07f7a43a781" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_667bb6b9-bd68-4853-99f1-d71e7a4f0d46" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_71c0736c-899c-4e40-9678-b07f7a43a781" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_667bb6b9-bd68-4853-99f1-d71e7a4f0d46" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_2f667a3f-aa08-4778-842a-b321f9076fe9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_71c0736c-899c-4e40-9678-b07f7a43a781" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_2f667a3f-aa08-4778-842a-b321f9076fe9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_32fc738b-6b10-43dd-bac6-9c367cf26101" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ImpairmentOfIntangibleAssetsFinitelived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_71c0736c-899c-4e40-9678-b07f7a43a781" xlink:to="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_32fc738b-6b10-43dd-bac6-9c367cf26101" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_266f3630-0ec4-408d-8d3f-33de1e30ddc8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_71c0736c-899c-4e40-9678-b07f7a43a781" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_266f3630-0ec4-408d-8d3f-33de1e30ddc8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_b595115f-922c-4f85-a6dc-9470a720f903" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_71c0736c-899c-4e40-9678-b07f7a43a781" xlink:to="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_b595115f-922c-4f85-a6dc-9470a720f903" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_cb8c015c-e98a-4972-961c-e9bc126be806" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_71c0736c-899c-4e40-9678-b07f7a43a781" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_cb8c015c-e98a-4972-961c-e9bc126be806" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/GOODWILLANDINTANGIBLEASSETSNarrativeDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#GOODWILLANDINTANGIBLEASSETSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/GOODWILLANDINTANGIBLEASSETSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_e9d88c59-1017-4fec-9940-751437b663cd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_e48bd6bb-385a-4f48-b43c-e01eeffa633d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_e9d88c59-1017-4fec-9940-751437b663cd" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_e48bd6bb-385a-4f48-b43c-e01eeffa633d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_7c41cf52-7cde-47d6-bae0-e83029b5a105" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_e48bd6bb-385a-4f48-b43c-e01eeffa633d" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_7c41cf52-7cde-47d6-bae0-e83029b5a105" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7c41cf52-7cde-47d6-bae0-e83029b5a105_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_7c41cf52-7cde-47d6-bae0-e83029b5a105" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7c41cf52-7cde-47d6-bae0-e83029b5a105_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9fd73682-e481-4b71-a8cb-1390707a86da" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_7c41cf52-7cde-47d6-bae0-e83029b5a105" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9fd73682-e481-4b71-a8cb-1390707a86da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_GreenComNetworksAGMember_ba5a9ea1-96b3-497b-bdf1-a453d2410af9" xlink:href="enph-20240630.xsd#enph_GreenComNetworksAGMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9fd73682-e481-4b71-a8cb-1390707a86da" xlink:to="loc_enph_GreenComNetworksAGMember_ba5a9ea1-96b3-497b-bdf1-a453d2410af9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_5788834b-065a-49f0-bdd4-ca83da259770" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_e48bd6bb-385a-4f48-b43c-e01eeffa633d" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_5788834b-065a-49f0-bdd4-ca83da259770" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5788834b-065a-49f0-bdd4-ca83da259770_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_5788834b-065a-49f0-bdd4-ca83da259770" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5788834b-065a-49f0-bdd4-ca83da259770_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0245f509-363b-4d4c-81f4-24b1fa4a14db" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_5788834b-065a-49f0-bdd4-ca83da259770" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0245f509-363b-4d4c-81f4-24b1fa4a14db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_f043e7d3-ca9d-4302-be31-6555ecb1966e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0245f509-363b-4d4c-81f4-24b1fa4a14db" xlink:to="loc_us-gaap_CustomerRelationshipsMember_f043e7d3-ca9d-4302-be31-6555ecb1966e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_486b8b7f-5d1e-423b-9ca1-9a40e2b3c436" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_e48bd6bb-385a-4f48-b43c-e01eeffa633d" xlink:to="loc_srt_MajorCustomersAxis_486b8b7f-5d1e-423b-9ca1-9a40e2b3c436" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_486b8b7f-5d1e-423b-9ca1-9a40e2b3c436_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_486b8b7f-5d1e-423b-9ca1-9a40e2b3c436" xlink:to="loc_srt_NameOfMajorCustomerDomain_486b8b7f-5d1e-423b-9ca1-9a40e2b3c436_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_0d290cb1-e378-41c7-9ca7-045558d8e600" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_486b8b7f-5d1e-423b-9ca1-9a40e2b3c436" xlink:to="loc_srt_NameOfMajorCustomerDomain_0d290cb1-e378-41c7-9ca7-045558d8e600" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_CustomerOneMember_61c6f825-c0e8-4324-9a3d-d6220a8a52c0" xlink:href="enph-20240630.xsd#enph_CustomerOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_0d290cb1-e378-41c7-9ca7-045558d8e600" xlink:to="loc_enph_CustomerOneMember_61c6f825-c0e8-4324-9a3d-d6220a8a52c0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss_35f04762-b2a7-4980-9a86-ebc3608f171c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_e9d88c59-1017-4fec-9940-751437b663cd" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss_35f04762-b2a7-4980-9a86-ebc3608f171c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_c90228f0-9533-47e0-8237-7dd5160de97b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_e9d88c59-1017-4fec-9940-751437b663cd" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_c90228f0-9533-47e0-8237-7dd5160de97b" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/GOODWILLANDINTANGIBLEASSETSAmortizationExpenseDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#GOODWILLANDINTANGIBLEASSETSAmortizationExpenseDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/GOODWILLANDINTANGIBLEASSETSAmortizationExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_faabc889-4870-4f4a-bbdb-8f9808e20c4b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_47e365ec-4add-4ff7-a344-09350e233145" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_faabc889-4870-4f4a-bbdb-8f9808e20c4b" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_47e365ec-4add-4ff7-a344-09350e233145" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_dd72aa9b-2fb4-4856-817e-bbab7e8a9ad8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_47e365ec-4add-4ff7-a344-09350e233145" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_dd72aa9b-2fb4-4856-817e-bbab7e8a9ad8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_dd72aa9b-2fb4-4856-817e-bbab7e8a9ad8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_dd72aa9b-2fb4-4856-817e-bbab7e8a9ad8" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_dd72aa9b-2fb4-4856-817e-bbab7e8a9ad8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_116912dd-15fa-4cc0-8bc8-be9d508fc84a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_dd72aa9b-2fb4-4856-817e-bbab7e8a9ad8" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_116912dd-15fa-4cc0-8bc8-be9d508fc84a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_b58ece86-abc1-438a-a4b8-cf321d313e79" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DevelopedTechnologyRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_116912dd-15fa-4cc0-8bc8-be9d508fc84a" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_b58ece86-abc1-438a-a4b8-cf321d313e79" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_1dad8826-567b-47fc-9b21-d4b5ef1de8ba" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_116912dd-15fa-4cc0-8bc8-be9d508fc84a" xlink:to="loc_us-gaap_CustomerRelationshipsMember_1dad8826-567b-47fc-9b21-d4b5ef1de8ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_70a13743-d01b-4037-aca4-9991c07f52e4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_116912dd-15fa-4cc0-8bc8-be9d508fc84a" xlink:to="loc_us-gaap_TradeNamesMember_70a13743-d01b-4037-aca4-9991c07f52e4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_09a10450-8144-4fc4-b184-e7a93a68121a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_faabc889-4870-4f4a-bbdb-8f9808e20c4b" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_09a10450-8144-4fc4-b184-e7a93a68121a" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/CASHEQUIVALENTSANDMARKETABLESECURITIESScheduleofInvestmentsDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#CASHEQUIVALENTSANDMARKETABLESECURITIESScheduleofInvestmentsDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/CASHEQUIVALENTSANDMARKETABLESECURITIESScheduleofInvestmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_e8e22c85-3ddb-4f28-93b3-cfb13c09273f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_7614ee6f-8165-4200-9356-c9cc3a1156f5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_e8e22c85-3ddb-4f28-93b3-cfb13c09273f" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_7614ee6f-8165-4200-9356-c9cc3a1156f5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_2177778f-9d57-4124-9f34-38154ca998a5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_7614ee6f-8165-4200-9356-c9cc3a1156f5" xlink:to="loc_us-gaap_FinancialInstrumentAxis_2177778f-9d57-4124-9f34-38154ca998a5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_2177778f-9d57-4124-9f34-38154ca998a5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_2177778f-9d57-4124-9f34-38154ca998a5" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_2177778f-9d57-4124-9f34-38154ca998a5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_b6710bc4-e2c3-4e26-b66d-964c2ba819ea" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_2177778f-9d57-4124-9f34-38154ca998a5" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_b6710bc4-e2c3-4e26-b66d-964c2ba819ea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_a5587d11-8d68-4dc8-859c-a72840b90249" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MoneyMarketFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_b6710bc4-e2c3-4e26-b66d-964c2ba819ea" xlink:to="loc_us-gaap_MoneyMarketFundsMember_a5587d11-8d68-4dc8-859c-a72840b90249" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CertificatesOfDepositMember_4058f6d6-806f-402e-b54b-bfef5de615ee" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CertificatesOfDepositMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_b6710bc4-e2c3-4e26-b66d-964c2ba819ea" xlink:to="loc_us-gaap_CertificatesOfDepositMember_4058f6d6-806f-402e-b54b-bfef5de615ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperMember_a922c665-cf70-40a0-8ac5-9235cbb1987a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommercialPaperMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_b6710bc4-e2c3-4e26-b66d-964c2ba819ea" xlink:to="loc_us-gaap_CommercialPaperMember_a922c665-cf70-40a0-8ac5-9235cbb1987a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_CorporateBondSecuritiesAndNoteSecuritiesMember_dc74c2b0-f6a0-4450-85f4-20cde43ae4be" xlink:href="enph-20240630.xsd#enph_CorporateBondSecuritiesAndNoteSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_b6710bc4-e2c3-4e26-b66d-964c2ba819ea" xlink:to="loc_enph_CorporateBondSecuritiesAndNoteSecuritiesMember_dc74c2b0-f6a0-4450-85f4-20cde43ae4be" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_ce04596d-c8b8-44f6-b7c7-faf3c6d375c9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_USTreasurySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_b6710bc4-e2c3-4e26-b66d-964c2ba819ea" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_ce04596d-c8b8-44f6-b7c7-faf3c6d375c9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_4783ae99-323f-4c13-b097-a2c34b9e9ec4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_USGovernmentAgenciesDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_b6710bc4-e2c3-4e26-b66d-964c2ba819ea" xlink:to="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_4783ae99-323f-4c13-b097-a2c34b9e9ec4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_be4f21bc-bf38-417e-8496-6b800e7183a3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_7614ee6f-8165-4200-9356-c9cc3a1156f5" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_be4f21bc-bf38-417e-8496-6b800e7183a3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_be4f21bc-bf38-417e-8496-6b800e7183a3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_be4f21bc-bf38-417e-8496-6b800e7183a3" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_be4f21bc-bf38-417e-8496-6b800e7183a3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_110bed89-ed80-4d41-8ad6-2219012d1e3d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_be4f21bc-bf38-417e-8496-6b800e7183a3" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_110bed89-ed80-4d41-8ad6-2219012d1e3d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsMember_71541b32-bb0a-4502-9c1d-9dfbe24e177e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_110bed89-ed80-4d41-8ad6-2219012d1e3d" xlink:to="loc_us-gaap_CashAndCashEquivalentsMember_71541b32-bb0a-4502-9c1d-9dfbe24e177e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_MarketableSecuritiesMember_6d59249b-6d1a-430f-88ec-eff56a7449bb" xlink:href="enph-20240630.xsd#enph_MarketableSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_110bed89-ed80-4d41-8ad6-2219012d1e3d" xlink:to="loc_enph_MarketableSecuritiesMember_6d59249b-6d1a-430f-88ec-eff56a7449bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_a182d518-c189-4daf-89aa-ce9572775c4b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_e8e22c85-3ddb-4f28-93b3-cfb13c09273f" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_a182d518-c189-4daf-89aa-ce9572775c4b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_325f3b9c-b0b5-4c38-8bad-362cc19a0cfe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_e8e22c85-3ddb-4f28-93b3-cfb13c09273f" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_325f3b9c-b0b5-4c38-8bad-362cc19a0cfe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_3a5a4325-1237-4759-be81-843bf6ae8bdd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_e8e22c85-3ddb-4f28-93b3-cfb13c09273f" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_3a5a4325-1237-4759-be81-843bf6ae8bdd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_bb023b75-01d4-4f01-8503-232b0631f545" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_e8e22c85-3ddb-4f28-93b3-cfb13c09273f" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_bb023b75-01d4-4f01-8503-232b0631f545" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/WARRANTYOBLIGATIONSNarrativeDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#WARRANTYOBLIGATIONSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/WARRANTYOBLIGATIONSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductWarrantyLiabilityLineItems_47652d1f-241d-4a41-a5c3-f17645c61601" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProductWarrantyLiabilityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductWarrantyLiabilityTable_0c57db32-e90f-4c1e-9e21-66a3e4a4804a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProductWarrantyLiabilityTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ProductWarrantyLiabilityLineItems_47652d1f-241d-4a41-a5c3-f17645c61601" xlink:to="loc_us-gaap_ProductWarrantyLiabilityTable_0c57db32-e90f-4c1e-9e21-66a3e4a4804a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_WarrantyVariableAxis_4e29389e-fda1-40d1-bd6e-1c4d5e9a1b30" xlink:href="enph-20240630.xsd#enph_WarrantyVariableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ProductWarrantyLiabilityTable_0c57db32-e90f-4c1e-9e21-66a3e4a4804a" xlink:to="loc_enph_WarrantyVariableAxis_4e29389e-fda1-40d1-bd6e-1c4d5e9a1b30" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_WarrantyVariableDomain_4e29389e-fda1-40d1-bd6e-1c4d5e9a1b30_default" xlink:href="enph-20240630.xsd#enph_WarrantyVariableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_enph_WarrantyVariableAxis_4e29389e-fda1-40d1-bd6e-1c4d5e9a1b30" xlink:to="loc_enph_WarrantyVariableDomain_4e29389e-fda1-40d1-bd6e-1c4d5e9a1b30_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_WarrantyVariableDomain_1f828939-863f-4c6c-881f-0a39e638f29a" xlink:href="enph-20240630.xsd#enph_WarrantyVariableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_enph_WarrantyVariableAxis_4e29389e-fda1-40d1-bd6e-1c4d5e9a1b30" xlink:to="loc_enph_WarrantyVariableDomain_1f828939-863f-4c6c-881f-0a39e638f29a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ProductReplacementCostsRelatedToEnphaseIQBatterySystemsMember_345a392e-9568-4277-9cd6-dceb3f215da0" xlink:href="enph-20240630.xsd#enph_ProductReplacementCostsRelatedToEnphaseIQBatterySystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_enph_WarrantyVariableDomain_1f828939-863f-4c6c-881f-0a39e638f29a" xlink:to="loc_enph_ProductReplacementCostsRelatedToEnphaseIQBatterySystemsMember_345a392e-9568-4277-9cd6-dceb3f215da0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_FieldPerformanceDataAndDiagnosticRootCauseFailureAnalysisRelatedToEnphaseIQBatteryStorageSystemsMember_cc9a08cb-f3e8-4bf3-9676-aa7982a75098" xlink:href="enph-20240630.xsd#enph_FieldPerformanceDataAndDiagnosticRootCauseFailureAnalysisRelatedToEnphaseIQBatteryStorageSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_enph_WarrantyVariableDomain_1f828939-863f-4c6c-881f-0a39e638f29a" xlink:to="loc_enph_FieldPerformanceDataAndDiagnosticRootCauseFailureAnalysisRelatedToEnphaseIQBatteryStorageSystemsMember_cc9a08cb-f3e8-4bf3-9676-aa7982a75098" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_FieldPerformanceDataAndDiagnosticRootCauseFailureAnalysisToOtherProductsMember_ee2c11c9-1bef-4658-ae6a-d7a116768c0a" xlink:href="enph-20240630.xsd#enph_FieldPerformanceDataAndDiagnosticRootCauseFailureAnalysisToOtherProductsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_enph_WarrantyVariableDomain_1f828939-863f-4c6c-881f-0a39e638f29a" xlink:to="loc_enph_FieldPerformanceDataAndDiagnosticRootCauseFailureAnalysisToOtherProductsMember_ee2c11c9-1bef-4658-ae6a-d7a116768c0a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ProductReplacementCostsRelatedToOtherProductsMember_377e4754-214b-4d5b-8b35-f7dc8fe93df5" xlink:href="enph-20240630.xsd#enph_ProductReplacementCostsRelatedToOtherProductsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_enph_WarrantyVariableDomain_1f828939-863f-4c6c-881f-0a39e638f29a" xlink:to="loc_enph_ProductReplacementCostsRelatedToOtherProductsMember_377e4754-214b-4d5b-8b35-f7dc8fe93df5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ChangeInWarrantyPeriodMember_1ca9b4a7-8863-46fc-aa96-7c6afcce9601" xlink:href="enph-20240630.xsd#enph_ChangeInWarrantyPeriodMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_enph_WarrantyVariableDomain_1f828939-863f-4c6c-881f-0a39e638f29a" xlink:to="loc_enph_ChangeInWarrantyPeriodMember_1ca9b4a7-8863-46fc-aa96-7c6afcce9601" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_eba7f0eb-c56a-4225-a3f9-afd846e602a3" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ProductWarrantyLiabilityTable_0c57db32-e90f-4c1e-9e21-66a3e4a4804a" xlink:to="loc_srt_ProductOrServiceAxis_eba7f0eb-c56a-4225-a3f9-afd846e602a3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_eba7f0eb-c56a-4225-a3f9-afd846e602a3_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_eba7f0eb-c56a-4225-a3f9-afd846e602a3" xlink:to="loc_srt_ProductsAndServicesDomain_eba7f0eb-c56a-4225-a3f9-afd846e602a3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_6d8964c5-4796-4afc-a916-6ba6e772397a" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_eba7f0eb-c56a-4225-a3f9-afd846e602a3" xlink:to="loc_srt_ProductsAndServicesDomain_6d8964c5-4796-4afc-a916-6ba6e772397a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_IQBatteryMember_774442f6-cffe-4066-a1c8-bc765bde92ba" xlink:href="enph-20240630.xsd#enph_IQBatteryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_6d8964c5-4796-4afc-a916-6ba6e772397a" xlink:to="loc_enph_IQBatteryMember_774442f6-cffe-4066-a1c8-bc765bde92ba" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_0c66df6c-994e-4efd-aed3-32ff283aec33" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ProductWarrantyLiabilityTable_0c57db32-e90f-4c1e-9e21-66a3e4a4804a" xlink:to="loc_srt_RangeAxis_0c66df6c-994e-4efd-aed3-32ff283aec33" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_0c66df6c-994e-4efd-aed3-32ff283aec33_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_0c66df6c-994e-4efd-aed3-32ff283aec33" xlink:to="loc_srt_RangeMember_0c66df6c-994e-4efd-aed3-32ff283aec33_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_45752306-5cb4-40be-8a11-aac65271a689" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_0c66df6c-994e-4efd-aed3-32ff283aec33" xlink:to="loc_srt_RangeMember_45752306-5cb4-40be-8a11-aac65271a689" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_aac5c523-6ba7-47bc-b723-91519df331b6" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_45752306-5cb4-40be-8a11-aac65271a689" xlink:to="loc_srt_MinimumMember_aac5c523-6ba7-47bc-b723-91519df331b6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_8165c70f-dca7-4540-a28d-659e79f01d67" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_45752306-5cb4-40be-8a11-aac65271a689" xlink:to="loc_srt_MaximumMember_8165c70f-dca7-4540-a28d-659e79f01d67" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease_1c263d47-bedc-48cb-8c3d-11f7e23b5e43" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductWarrantyLiabilityLineItems_47652d1f-241d-4a41-a5c3-f17645c61601" xlink:to="loc_us-gaap_ProductWarrantyAccrualPreexistingIncreaseDecrease_1c263d47-bedc-48cb-8c3d-11f7e23b5e43" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ProductWarrantyTerm_176398e9-37cc-47d6-a071-76079ab30156" xlink:href="enph-20240630.xsd#enph_ProductWarrantyTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductWarrantyLiabilityLineItems_47652d1f-241d-4a41-a5c3-f17645c61601" xlink:to="loc_enph_ProductWarrantyTerm_176398e9-37cc-47d6-a071-76079ab30156" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/FAIRVALUEMEASUREMENTSScheduleofAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#FAIRVALUEMEASUREMENTSScheduleofAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/FAIRVALUEMEASUREMENTSScheduleofAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_2a5d6486-e12d-4e94-8c09-d3e767fa37e5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_26498c00-dc89-448a-ab67-18fda7ce229d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_2a5d6486-e12d-4e94-8c09-d3e767fa37e5" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_26498c00-dc89-448a-ab67-18fda7ce229d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_2b058f2b-adb7-4a0d-b4be-514170467101" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_26498c00-dc89-448a-ab67-18fda7ce229d" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_2b058f2b-adb7-4a0d-b4be-514170467101" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_2b058f2b-adb7-4a0d-b4be-514170467101_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_2b058f2b-adb7-4a0d-b4be-514170467101" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_2b058f2b-adb7-4a0d-b4be-514170467101_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_609d070e-3cad-4e86-953a-751a692698f9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_2b058f2b-adb7-4a0d-b4be-514170467101" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_609d070e-3cad-4e86-953a-751a692698f9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_09f19051-47ca-4afa-b5e4-a1f3d4a19249" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_609d070e-3cad-4e86-953a-751a692698f9" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_09f19051-47ca-4afa-b5e4-a1f3d4a19249" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_96707db3-722b-46de-a940-c9b48d7af712" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_26498c00-dc89-448a-ab67-18fda7ce229d" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_96707db3-722b-46de-a940-c9b48d7af712" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_96707db3-722b-46de-a940-c9b48d7af712_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_96707db3-722b-46de-a940-c9b48d7af712" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_96707db3-722b-46de-a940-c9b48d7af712_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_a28e555b-b295-413c-a30d-7a9d246724c2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_96707db3-722b-46de-a940-c9b48d7af712" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_a28e555b-b295-413c-a30d-7a9d246724c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_30095f0e-a2ea-4de7-965d-e41e7240a508" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_a28e555b-b295-413c-a30d-7a9d246724c2" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_30095f0e-a2ea-4de7-965d-e41e7240a508" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_e32b53b3-a9a4-4a5f-be4e-0a79b0098984" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_a28e555b-b295-413c-a30d-7a9d246724c2" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_e32b53b3-a9a4-4a5f-be4e-0a79b0098984" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_72dd2f1e-e8d2-49ec-90cf-eba817391705" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_a28e555b-b295-413c-a30d-7a9d246724c2" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_72dd2f1e-e8d2-49ec-90cf-eba817391705" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAxis_f45d5182-d0d9-4272-a4ee-00cfbee3b8ee" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndCashEquivalentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_26498c00-dc89-448a-ab67-18fda7ce229d" xlink:to="loc_us-gaap_CashAndCashEquivalentsAxis_f45d5182-d0d9-4272-a4ee-00cfbee3b8ee" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_f45d5182-d0d9-4272-a4ee-00cfbee3b8ee_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_f45d5182-d0d9-4272-a4ee-00cfbee3b8ee" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_f45d5182-d0d9-4272-a4ee-00cfbee3b8ee_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_fa157129-2ef5-4bf2-b034-5a7c88259a0b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_f45d5182-d0d9-4272-a4ee-00cfbee3b8ee" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_fa157129-2ef5-4bf2-b034-5a7c88259a0b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_7d26f0e8-5e76-43cd-8d2e-54cf8b6a9203" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MoneyMarketFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_fa157129-2ef5-4bf2-b034-5a7c88259a0b" xlink:to="loc_us-gaap_MoneyMarketFundsMember_7d26f0e8-5e76-43cd-8d2e-54cf8b6a9203" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CertificatesOfDepositMember_00bfae60-5f94-489a-8b69-ca938cb5d825" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CertificatesOfDepositMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_fa157129-2ef5-4bf2-b034-5a7c88259a0b" xlink:to="loc_us-gaap_CertificatesOfDepositMember_00bfae60-5f94-489a-8b69-ca938cb5d825" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperMember_54ea505b-c434-45ea-b08a-18b473f66208" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommercialPaperMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_fa157129-2ef5-4bf2-b034-5a7c88259a0b" xlink:to="loc_us-gaap_CommercialPaperMember_54ea505b-c434-45ea-b08a-18b473f66208" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_CorporateBondSecuritiesAndNoteSecuritiesMember_74b713f6-9258-4bab-b46f-f1529ec1a45d" xlink:href="enph-20240630.xsd#enph_CorporateBondSecuritiesAndNoteSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_fa157129-2ef5-4bf2-b034-5a7c88259a0b" xlink:to="loc_enph_CorporateBondSecuritiesAndNoteSecuritiesMember_74b713f6-9258-4bab-b46f-f1529ec1a45d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_a70b69c4-d439-4377-8a0a-44c3007ccbb7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_USTreasurySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_fa157129-2ef5-4bf2-b034-5a7c88259a0b" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_a70b69c4-d439-4377-8a0a-44c3007ccbb7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_09467d0d-7e48-41a4-8f21-5aae82957e45" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_26498c00-dc89-448a-ab67-18fda7ce229d" xlink:to="loc_us-gaap_FinancialInstrumentAxis_09467d0d-7e48-41a4-8f21-5aae82957e45" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_09467d0d-7e48-41a4-8f21-5aae82957e45_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_09467d0d-7e48-41a4-8f21-5aae82957e45" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_09467d0d-7e48-41a4-8f21-5aae82957e45_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1b9f68ce-aa11-4bab-975a-37e6935d4818" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_09467d0d-7e48-41a4-8f21-5aae82957e45" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1b9f68ce-aa11-4bab-975a-37e6935d4818" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CertificatesOfDepositMember_10955697-8a95-46c6-b8a1-a563da7cda5e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CertificatesOfDepositMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1b9f68ce-aa11-4bab-975a-37e6935d4818" xlink:to="loc_us-gaap_CertificatesOfDepositMember_10955697-8a95-46c6-b8a1-a563da7cda5e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperMember_7b805191-d293-43f6-9d24-04a3d336a868" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommercialPaperMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1b9f68ce-aa11-4bab-975a-37e6935d4818" xlink:to="loc_us-gaap_CommercialPaperMember_7b805191-d293-43f6-9d24-04a3d336a868" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_CorporateBondSecuritiesAndNoteSecuritiesMember_2d598cdb-5167-4f26-9e84-ce4ab65c3fe8" xlink:href="enph-20240630.xsd#enph_CorporateBondSecuritiesAndNoteSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1b9f68ce-aa11-4bab-975a-37e6935d4818" xlink:to="loc_enph_CorporateBondSecuritiesAndNoteSecuritiesMember_2d598cdb-5167-4f26-9e84-ce4ab65c3fe8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_1507d352-31a5-4b65-9125-60ca6afc2f9f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_USTreasurySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1b9f68ce-aa11-4bab-975a-37e6935d4818" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_1507d352-31a5-4b65-9125-60ca6afc2f9f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_6bf0ab70-cdd3-41cb-86f8-5ef9b0cb0cf3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_USGovernmentAgenciesDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1b9f68ce-aa11-4bab-975a-37e6935d4818" xlink:to="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_6bf0ab70-cdd3-41cb-86f8-5ef9b0cb0cf3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_0ceb866f-6ccc-446b-adf0-2cf25e6aed36" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_2a5d6486-e12d-4e94-8c09-d3e767fa37e5" xlink:to="loc_us-gaap_AssetsAbstract_0ceb866f-6ccc-446b-adf0-2cf25e6aed36" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_62f3779d-e2f9-402b-a9c8-a9338ec1b144" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_0ceb866f-6ccc-446b-adf0-2cf25e6aed36" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_62f3779d-e2f9-402b-a9c8-a9338ec1b144" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_0b1256f9-4710-4021-a6a3-110f3146ad5f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_0ceb866f-6ccc-446b-adf0-2cf25e6aed36" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_0b1256f9-4710-4021-a6a3-110f3146ad5f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecurities_0297fada-e635-4faa-a92b-71733eee1420" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_0ceb866f-6ccc-446b-adf0-2cf25e6aed36" xlink:to="loc_us-gaap_DebtSecurities_0297fada-e635-4faa-a92b-71733eee1420" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_c6ba80c9-1381-4d3b-9349-0e4a721cfcb3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_0ceb866f-6ccc-446b-adf0-2cf25e6aed36" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_c6ba80c9-1381-4d3b-9349-0e4a721cfcb3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract_c79a361c-fe27-4719-87b3-af0cd19b717f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_2a5d6486-e12d-4e94-8c09-d3e767fa37e5" xlink:to="loc_us-gaap_LiabilitiesAbstract_c79a361c-fe27-4719-87b3-af0cd19b717f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_WarrantyObligationsAbstract_f0c67c6f-8a35-4d72-9ece-323cd0781e31" xlink:href="enph-20240630.xsd#enph_WarrantyObligationsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_c79a361c-fe27-4719-87b3-af0cd19b717f" xlink:to="loc_enph_WarrantyObligationsAbstract_f0c67c6f-8a35-4d72-9ece-323cd0781e31" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_StandardAndExtendedProductWarrantyAccrualCurrentFairValueDisclosure_25f25812-e8ea-45f6-9a74-27177836e466" xlink:href="enph-20240630.xsd#enph_StandardAndExtendedProductWarrantyAccrualCurrentFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_enph_WarrantyObligationsAbstract_f0c67c6f-8a35-4d72-9ece-323cd0781e31" xlink:to="loc_enph_StandardAndExtendedProductWarrantyAccrualCurrentFairValueDisclosure_25f25812-e8ea-45f6-9a74-27177836e466" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_StandardAndExtendedProductWarrantyAccrualNoncurrentFairValueDisclosure_b66d4041-59db-4756-8a96-953a0dd3691e" xlink:href="enph-20240630.xsd#enph_StandardAndExtendedProductWarrantyAccrualNoncurrentFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_enph_WarrantyObligationsAbstract_f0c67c6f-8a35-4d72-9ece-323cd0781e31" xlink:to="loc_enph_StandardAndExtendedProductWarrantyAccrualNoncurrentFairValueDisclosure_b66d4041-59db-4756-8a96-953a0dd3691e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_StandardAndExtendedProductWarrantyAccrualFairValueDisclosure_50b47acf-34ba-45ee-b365-8e1fad1b5175" xlink:href="enph-20240630.xsd#enph_StandardAndExtendedProductWarrantyAccrualFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_enph_WarrantyObligationsAbstract_f0c67c6f-8a35-4d72-9ece-323cd0781e31" xlink:to="loc_enph_StandardAndExtendedProductWarrantyAccrualFairValueDisclosure_50b47acf-34ba-45ee-b365-8e1fad1b5175" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_5dbc1eb0-127e-48cb-849b-dc426df7e42f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_c79a361c-fe27-4719-87b3-af0cd19b717f" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosure_5dbc1eb0-127e-48cb-849b-dc426df7e42f" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/FAIRVALUEMEASUREMENTSNarrativeDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#FAIRVALUEMEASUREMENTSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/FAIRVALUEMEASUREMENTSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_4a250013-8aa8-4375-a1d4-2120ef51021b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_79864ad4-9152-40cf-b32b-9df5e3463d5d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_4a250013-8aa8-4375-a1d4-2120ef51021b" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_79864ad4-9152-40cf-b32b-9df5e3463d5d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_05ce490a-f9d1-4218-bd0e-d47310fdcc5e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_79864ad4-9152-40cf-b32b-9df5e3463d5d" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_05ce490a-f9d1-4218-bd0e-d47310fdcc5e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_05ce490a-f9d1-4218-bd0e-d47310fdcc5e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_05ce490a-f9d1-4218-bd0e-d47310fdcc5e" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_05ce490a-f9d1-4218-bd0e-d47310fdcc5e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_22b440a3-4498-4fb7-b693-b3760e2d9e23" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_05ce490a-f9d1-4218-bd0e-d47310fdcc5e" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_22b440a3-4498-4fb7-b693-b3760e2d9e23" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_6c6f66c2-c823-4bd4-8809-b132ee8201f9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_22b440a3-4498-4fb7-b693-b3760e2d9e23" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_6c6f66c2-c823-4bd4-8809-b132ee8201f9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_29caa45c-6c1e-4a7a-b96f-36a7744a4819" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_79864ad4-9152-40cf-b32b-9df5e3463d5d" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_29caa45c-6c1e-4a7a-b96f-36a7744a4819" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_29caa45c-6c1e-4a7a-b96f-36a7744a4819_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_29caa45c-6c1e-4a7a-b96f-36a7744a4819" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_29caa45c-6c1e-4a7a-b96f-36a7744a4819_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_18394663-a1d6-43f5-819a-fd33966b0b7c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_29caa45c-6c1e-4a7a-b96f-36a7744a4819" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_18394663-a1d6-43f5-819a-fd33966b0b7c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_71c21447-ac17-4c40-b653-e03073447c5d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_18394663-a1d6-43f5-819a-fd33966b0b7c" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_71c21447-ac17-4c40-b653-e03073447c5d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_3f5e0ede-9c2d-406a-bfe1-5e9be22723ea" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_79864ad4-9152-40cf-b32b-9df5e3463d5d" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_3f5e0ede-9c2d-406a-bfe1-5e9be22723ea" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_3f5e0ede-9c2d-406a-bfe1-5e9be22723ea_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_3f5e0ede-9c2d-406a-bfe1-5e9be22723ea" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_3f5e0ede-9c2d-406a-bfe1-5e9be22723ea_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_c422d6f2-189c-4ad5-b75b-758e773a897f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_3f5e0ede-9c2d-406a-bfe1-5e9be22723ea" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_c422d6f2-189c-4ad5-b75b-758e773a897f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleNotesPayableMember_b0daf95d-6f51-4331-8365-ce5f14dd5604" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConvertibleNotesPayableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_c422d6f2-189c-4ad5-b75b-758e773a897f" xlink:to="loc_us-gaap_ConvertibleNotesPayableMember_b0daf95d-6f51-4331-8365-ce5f14dd5604" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_d69567de-66ba-40ae-b8bf-c8cb7419c78a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_79864ad4-9152-40cf-b32b-9df5e3463d5d" xlink:to="loc_us-gaap_DebtInstrumentAxis_d69567de-66ba-40ae-b8bf-c8cb7419c78a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_d69567de-66ba-40ae-b8bf-c8cb7419c78a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_d69567de-66ba-40ae-b8bf-c8cb7419c78a" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_d69567de-66ba-40ae-b8bf-c8cb7419c78a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_df7844a3-b8ed-4dce-93ae-190bb02bc07b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_d69567de-66ba-40ae-b8bf-c8cb7419c78a" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_df7844a3-b8ed-4dce-93ae-190bb02bc07b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2028Member_9669943e-26ae-4285-b323-c959f19137a4" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_df7844a3-b8ed-4dce-93ae-190bb02bc07b" xlink:to="loc_enph_ConvertibleSeniorNotesDue2028Member_9669943e-26ae-4285-b323-c959f19137a4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2026Member_ffc0cd67-5411-4a4c-af5f-1cb723de5f2b" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_df7844a3-b8ed-4dce-93ae-190bb02bc07b" xlink:to="loc_enph_ConvertibleSeniorNotesDue2026Member_ffc0cd67-5411-4a4c-af5f-1cb723de5f2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2025Member_4bc49050-1226-4c29-9fdd-86c502e6cd33" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_df7844a3-b8ed-4dce-93ae-190bb02bc07b" xlink:to="loc_enph_ConvertibleSeniorNotesDue2025Member_4bc49050-1226-4c29-9fdd-86c502e6cd33" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_427574f4-26a6-4b08-9c68-59c5a3df203c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_79864ad4-9152-40cf-b32b-9df5e3463d5d" xlink:to="loc_us-gaap_FinancialInstrumentAxis_427574f4-26a6-4b08-9c68-59c5a3df203c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_427574f4-26a6-4b08-9c68-59c5a3df203c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_427574f4-26a6-4b08-9c68-59c5a3df203c" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_427574f4-26a6-4b08-9c68-59c5a3df203c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_fad6178a-10a7-4410-b791-1bd73a11f913" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_427574f4-26a6-4b08-9c68-59c5a3df203c" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_fad6178a-10a7-4410-b791-1bd73a11f913" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_PrivatelyHeldCompanyMember_fb666ac7-e110-48ec-b8b5-3c2602639e0f" xlink:href="enph-20240630.xsd#enph_PrivatelyHeldCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_fad6178a-10a7-4410-b791-1bd73a11f913" xlink:to="loc_enph_PrivatelyHeldCompanyMember_fb666ac7-e110-48ec-b8b5-3c2602639e0f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesPayableFairValueDisclosure_c45ab55c-8ba4-4668-bba3-98881b69b307" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NotesPayableFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_4a250013-8aa8-4375-a1d4-2120ef51021b" xlink:to="loc_us-gaap_NotesPayableFairValueDisclosure_c45ab55c-8ba4-4668-bba3-98881b69b307" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecurities_e61e46f3-b780-45d5-bc5e-4762af414101" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_4a250013-8aa8-4375-a1d4-2120ef51021b" xlink:to="loc_us-gaap_DebtSecurities_e61e46f3-b780-45d5-bc5e-4762af414101" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TangibleAssetImpairmentCharges_eed7a30e-ccfd-448c-b965-5d908564be0e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TangibleAssetImpairmentCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_4a250013-8aa8-4375-a1d4-2120ef51021b" xlink:to="loc_us-gaap_TangibleAssetImpairmentCharges_eed7a30e-ccfd-448c-b965-5d908564be0e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_WarrantyObligationsAtFairValueIncreaseInFairValueLiabilityResultingFromOnePercentagePointIncreaseInProfitElementAndRiskPremium_02b9dcc2-9000-4197-9330-290aa2b823b9" xlink:href="enph-20240630.xsd#enph_WarrantyObligationsAtFairValueIncreaseInFairValueLiabilityResultingFromOnePercentagePointIncreaseInProfitElementAndRiskPremium"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_4a250013-8aa8-4375-a1d4-2120ef51021b" xlink:to="loc_enph_WarrantyObligationsAtFairValueIncreaseInFairValueLiabilityResultingFromOnePercentagePointIncreaseInProfitElementAndRiskPremium_02b9dcc2-9000-4197-9330-290aa2b823b9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_WarrantyObligationsAtFairValueDecreaseInFairValueLiabilityResultingFromOnePercentagePointDecreaseInProfitElementAndRiskPremium_82918ecf-a154-4932-aee6-6b9c747dc3b0" xlink:href="enph-20240630.xsd#enph_WarrantyObligationsAtFairValueDecreaseInFairValueLiabilityResultingFromOnePercentagePointDecreaseInProfitElementAndRiskPremium"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_4a250013-8aa8-4375-a1d4-2120ef51021b" xlink:to="loc_enph_WarrantyObligationsAtFairValueDecreaseInFairValueLiabilityResultingFromOnePercentagePointDecreaseInProfitElementAndRiskPremium_82918ecf-a154-4932-aee6-6b9c747dc3b0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_WarrantyObligationsAtFairValueDecreaseInFairValueResultingFromOnePercentagePointIncreaseInDiscountRate_bfd33a26-c324-49ed-8673-97a8bb65deb8" xlink:href="enph-20240630.xsd#enph_WarrantyObligationsAtFairValueDecreaseInFairValueResultingFromOnePercentagePointIncreaseInDiscountRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_4a250013-8aa8-4375-a1d4-2120ef51021b" xlink:to="loc_enph_WarrantyObligationsAtFairValueDecreaseInFairValueResultingFromOnePercentagePointIncreaseInDiscountRate_bfd33a26-c324-49ed-8673-97a8bb65deb8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_WarrantyObligationsAtFairValueIncreaseInFairValueResultingFromOnePercentagePointDecreaseInDiscountRate_d5a76ce7-3efe-4da3-9ac9-c247259c1ab1" xlink:href="enph-20240630.xsd#enph_WarrantyObligationsAtFairValueIncreaseInFairValueResultingFromOnePercentagePointDecreaseInDiscountRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_4a250013-8aa8-4375-a1d4-2120ef51021b" xlink:to="loc_enph_WarrantyObligationsAtFairValueIncreaseInFairValueResultingFromOnePercentagePointDecreaseInDiscountRate_d5a76ce7-3efe-4da3-9ac9-c247259c1ab1" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/FAIRVALUEMEASUREMENTSDebtSecuritiesScheduleofFairValueDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#FAIRVALUEMEASUREMENTSDebtSecuritiesScheduleofFairValueDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/FAIRVALUEMEASUREMENTSDebtSecuritiesScheduleofFairValueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_ee46ab52-d865-4843-8b8a-1b19776e34f7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable_7721a872-cc60-458c-a5f5-c3efd4329bd9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_ee46ab52-d865-4843-8b8a-1b19776e34f7" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable_7721a872-cc60-458c-a5f5-c3efd4329bd9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_066d1024-0785-4b4d-a5f1-ca634f69f11c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable_7721a872-cc60-458c-a5f5-c3efd4329bd9" xlink:to="loc_us-gaap_FinancialInstrumentAxis_066d1024-0785-4b4d-a5f1-ca634f69f11c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_066d1024-0785-4b4d-a5f1-ca634f69f11c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_066d1024-0785-4b4d-a5f1-ca634f69f11c" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_066d1024-0785-4b4d-a5f1-ca634f69f11c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_3869ec39-f349-4e4e-be2b-a41944d011e5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_066d1024-0785-4b4d-a5f1-ca634f69f11c" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_3869ec39-f349-4e4e-be2b-a41944d011e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesMember_f04e59d2-1e6b-4020-be8c-747309b458d6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_3869ec39-f349-4e4e-be2b-a41944d011e5" xlink:to="loc_us-gaap_DebtSecuritiesMember_f04e59d2-1e6b-4020-be8c-747309b458d6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_b1f4ea70-30fd-4a3b-be89-1fcfd3aa223c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_ee46ab52-d865-4843-8b8a-1b19776e34f7" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_b1f4ea70-30fd-4a3b-be89-1fcfd3aa223c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_8e524ec1-6a3c-4ad7-a717-5d7c9341a5c9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_b1f4ea70-30fd-4a3b-be89-1fcfd3aa223c" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_8e524ec1-6a3c-4ad7-a717-5d7c9341a5c9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1_3eac4bd3-4908-4314-8aae-894cfb9b9de9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_b1f4ea70-30fd-4a3b-be89-1fcfd3aa223c" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1_3eac4bd3-4908-4314-8aae-894cfb9b9de9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_c20730cb-39aa-4aaf-a139-0f20250f2810" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/FAIRVALUEMEASUREMENTSScheduleofChangesinNonfinancialLiabilitiesRelatedtoWarrantObligationsMeasuredatFairValueonaRecurringBasisUsingSignificantUnobservableInputsDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#FAIRVALUEMEASUREMENTSScheduleofChangesinNonfinancialLiabilitiesRelatedtoWarrantObligationsMeasuredatFairValueonaRecurringBasisUsingSignificantUnobservableInputsDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/FAIRVALUEMEASUREMENTSScheduleofChangesinNonfinancialLiabilitiesRelatedtoWarrantObligationsMeasuredatFairValueonaRecurringBasisUsingSignificantUnobservableInputsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_a2d91ad6-a69b-41f0-8f27-0458a95e1eca" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_d89e90be-ac85-4161-8d3a-743c7fb1b021" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_a2d91ad6-a69b-41f0-8f27-0458a95e1eca" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_d89e90be-ac85-4161-8d3a-743c7fb1b021" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_d793a3f9-05c5-48ad-a242-2f49375731f1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_d89e90be-ac85-4161-8d3a-743c7fb1b021" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_d793a3f9-05c5-48ad-a242-2f49375731f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_d793a3f9-05c5-48ad-a242-2f49375731f1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_d793a3f9-05c5-48ad-a242-2f49375731f1" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_d793a3f9-05c5-48ad-a242-2f49375731f1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_c933f421-d3e8-45ff-8b8a-26e526a9f094" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_d793a3f9-05c5-48ad-a242-2f49375731f1" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_c933f421-d3e8-45ff-8b8a-26e526a9f094" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_6a5bfc84-313c-408f-a363-31dc30c830a4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_c933f421-d3e8-45ff-8b8a-26e526a9f094" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_6a5bfc84-313c-408f-a363-31dc30c830a4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByLiabilityClassAxis_53c34d0c-cbef-4fec-8384-2781fff01062" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByLiabilityClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_d89e90be-ac85-4161-8d3a-743c7fb1b021" xlink:to="loc_us-gaap_FairValueByLiabilityClassAxis_53c34d0c-cbef-4fec-8384-2781fff01062" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_53c34d0c-cbef-4fec-8384-2781fff01062_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_53c34d0c-cbef-4fec-8384-2781fff01062" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_53c34d0c-cbef-4fec-8384-2781fff01062_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_03861df1-0fad-41b5-8efb-b3d7f8247214" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_53c34d0c-cbef-4fec-8384-2781fff01062" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_03861df1-0fad-41b5-8efb-b3d7f8247214" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantyRightsAndObligationsFairValueOptionMember_86f7944e-6cdc-4f24-8143-5df782a9afc2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WarrantyRightsAndObligationsFairValueOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_03861df1-0fad-41b5-8efb-b3d7f8247214" xlink:to="loc_us-gaap_WarrantyRightsAndObligationsFairValueOptionMember_86f7944e-6cdc-4f24-8143-5df782a9afc2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_5dc46bed-5f4b-4f4b-af5a-6e2252c87d12" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_d89e90be-ac85-4161-8d3a-743c7fb1b021" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_5dc46bed-5f4b-4f4b-af5a-6e2252c87d12" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_5dc46bed-5f4b-4f4b-af5a-6e2252c87d12_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_5dc46bed-5f4b-4f4b-af5a-6e2252c87d12" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_5dc46bed-5f4b-4f4b-af5a-6e2252c87d12_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_a38b0f04-cb62-4814-9be9-f1e991b5931e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_5dc46bed-5f4b-4f4b-af5a-6e2252c87d12" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_a38b0f04-cb62-4814-9be9-f1e991b5931e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_14119130-6d96-4236-aeb0-f6c11ab6a7e9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_a38b0f04-cb62-4814-9be9-f1e991b5931e" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_14119130-6d96-4236-aeb0-f6c11ab6a7e9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_c108cbce-9e17-477a-9985-0b02cff5afe6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_a2d91ad6-a69b-41f0-8f27-0458a95e1eca" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_c108cbce-9e17-477a-9985-0b02cff5afe6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_81ffff53-ff61-4a86-92cc-a551be969189" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_c108cbce-9e17-477a-9985-0b02cff5afe6" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_81ffff53-ff61-4a86-92cc-a551be969189" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisWarrantiesIssued_834061e3-e6d7-4142-b31f-2967a1a4a34f" xlink:href="enph-20240630.xsd#enph_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisWarrantiesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_c108cbce-9e17-477a-9985-0b02cff5afe6" xlink:to="loc_enph_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisWarrantiesIssued_834061e3-e6d7-4142-b31f-2967a1a4a34f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityChangeInEstimate_162ad798-71b6-45be-8e3a-36d060cc9da3" xlink:href="enph-20240630.xsd#enph_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityChangeInEstimate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_c108cbce-9e17-477a-9985-0b02cff5afe6" xlink:to="loc_enph_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityChangeInEstimate_162ad798-71b6-45be-8e3a-36d060cc9da3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements_144fb70c-5d55-4bd5-8293-a11c5a3633fa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_c108cbce-9e17-477a-9985-0b02cff5afe6" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements_144fb70c-5d55-4bd5-8293-a11c5a3633fa" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_f89a0ba5-714a-4420-bfb1-dd6f4c333e11" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_c108cbce-9e17-477a-9985-0b02cff5afe6" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_f89a0ba5-714a-4420-bfb1-dd6f4c333e11" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_StandardProductWarrantyAccrualChangeInDiscountRate_63b6216e-d9f5-4e3f-9110-111b8d9e568c" xlink:href="enph-20240630.xsd#enph_StandardProductWarrantyAccrualChangeInDiscountRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_c108cbce-9e17-477a-9985-0b02cff5afe6" xlink:to="loc_enph_StandardProductWarrantyAccrualChangeInDiscountRate_63b6216e-d9f5-4e3f-9110-111b8d9e568c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisIncreaseDecreaseInOther_792725d1-c9d9-4f20-b36d-4cf00b7568d1" xlink:href="enph-20240630.xsd#enph_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisIncreaseDecreaseInOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_c108cbce-9e17-477a-9985-0b02cff5afe6" xlink:to="loc_enph_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisIncreaseDecreaseInOther_792725d1-c9d9-4f20-b36d-4cf00b7568d1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_5396a5d5-364f-4d91-9700-f837f1bc8b87" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/FAIRVALUEMEASUREMENTSSummaryofSignificantUnobservableInputsusedintheFairValueMeasurementofLiabilitiesDesignatedasLevel3Details" xlink:type="simple" xlink:href="enph-20240630.xsd#FAIRVALUEMEASUREMENTSSummaryofSignificantUnobservableInputsusedintheFairValueMeasurementofLiabilitiesDesignatedasLevel3Details"/>
  <link:definitionLink xlink:role="http://enphase.com/role/FAIRVALUEMEASUREMENTSSummaryofSignificantUnobservableInputsusedintheFairValueMeasurementofLiabilitiesDesignatedasLevel3Details" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_0650d10f-3895-474a-abdb-2e81cdfc8dfb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_da8239c0-7672-4590-9a04-e1fa5dc50616" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_0650d10f-3895-474a-abdb-2e81cdfc8dfb" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_da8239c0-7672-4590-9a04-e1fa5dc50616" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_1458fb82-11fb-47ee-ac3f-724e943a0700" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_da8239c0-7672-4590-9a04-e1fa5dc50616" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_1458fb82-11fb-47ee-ac3f-724e943a0700" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_1458fb82-11fb-47ee-ac3f-724e943a0700_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_1458fb82-11fb-47ee-ac3f-724e943a0700" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_1458fb82-11fb-47ee-ac3f-724e943a0700_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_93ca025c-073c-4efd-afc3-a14a87c2201a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_1458fb82-11fb-47ee-ac3f-724e943a0700" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_93ca025c-073c-4efd-afc3-a14a87c2201a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_MeasurementInputProfitElementAndRiskPremiumMember_604587b5-b718-4695-971b-171743f872c3" xlink:href="enph-20240630.xsd#enph_MeasurementInputProfitElementAndRiskPremiumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_93ca025c-073c-4efd-afc3-a14a87c2201a" xlink:to="loc_enph_MeasurementInputProfitElementAndRiskPremiumMember_604587b5-b718-4695-971b-171743f872c3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputEntityCreditRiskMember_47873e6c-1308-4b88-b841-88997a378715" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputEntityCreditRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_93ca025c-073c-4efd-afc3-a14a87c2201a" xlink:to="loc_us-gaap_MeasurementInputEntityCreditRiskMember_47873e6c-1308-4b88-b841-88997a378715" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_6a690ed1-a60e-426e-96ee-0d67fa9df89b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_da8239c0-7672-4590-9a04-e1fa5dc50616" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_6a690ed1-a60e-426e-96ee-0d67fa9df89b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_6a690ed1-a60e-426e-96ee-0d67fa9df89b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_6a690ed1-a60e-426e-96ee-0d67fa9df89b" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_6a690ed1-a60e-426e-96ee-0d67fa9df89b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_570dedba-f14e-453c-88ad-1108469b24c0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_6a690ed1-a60e-426e-96ee-0d67fa9df89b" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_570dedba-f14e-453c-88ad-1108469b24c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_8aa7d2e9-db99-4fda-912c-8c78b977c1df" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_570dedba-f14e-453c-88ad-1108469b24c0" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_8aa7d2e9-db99-4fda-912c-8c78b977c1df" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e019554a-1f31-415c-8580-49b6fb0205b0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_da8239c0-7672-4590-9a04-e1fa5dc50616" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e019554a-1f31-415c-8580-49b6fb0205b0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_e019554a-1f31-415c-8580-49b6fb0205b0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e019554a-1f31-415c-8580-49b6fb0205b0" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_e019554a-1f31-415c-8580-49b6fb0205b0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1f184f2a-af04-49fd-be6a-de4d0097ba38" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e019554a-1f31-415c-8580-49b6fb0205b0" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1f184f2a-af04-49fd-be6a-de4d0097ba38" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_da30cf8d-f576-41ac-9d84-a8519e76809d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1f184f2a-af04-49fd-be6a-de4d0097ba38" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_da30cf8d-f576-41ac-9d84-a8519e76809d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_1aa36e02-b3a1-44c4-83f8-2e36627433a9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_da8239c0-7672-4590-9a04-e1fa5dc50616" xlink:to="loc_us-gaap_FinancialInstrumentAxis_1aa36e02-b3a1-44c4-83f8-2e36627433a9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1aa36e02-b3a1-44c4-83f8-2e36627433a9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_1aa36e02-b3a1-44c4-83f8-2e36627433a9" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1aa36e02-b3a1-44c4-83f8-2e36627433a9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1779ab57-100d-40de-935d-83da5cfaef70" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_1aa36e02-b3a1-44c4-83f8-2e36627433a9" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1779ab57-100d-40de-935d-83da5cfaef70" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantyRightsAndObligationsFairValueOptionMember_bf02ea04-0d49-48a5-8f74-bdeb37b49462" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WarrantyRightsAndObligationsFairValueOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1779ab57-100d-40de-935d-83da5cfaef70" xlink:to="loc_us-gaap_WarrantyRightsAndObligationsFairValueOptionMember_bf02ea04-0d49-48a5-8f74-bdeb37b49462" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ProductWarrantyObligationsMeasurementInput_bf31932c-e99f-48d5-9243-69186fa436b9" xlink:href="enph-20240630.xsd#enph_ProductWarrantyObligationsMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_0650d10f-3895-474a-abdb-2e81cdfc8dfb" xlink:to="loc_enph_ProductWarrantyObligationsMeasurementInput_bf31932c-e99f-48d5-9243-69186fa436b9" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/RESTRUCTURINGANDASSETIMPAIRMENTCHARGESRestructuringAndAssetImpairmentChargesDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#RESTRUCTURINGANDASSETIMPAIRMENTCHARGESRestructuringAndAssetImpairmentChargesDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/RESTRUCTURINGANDASSETIMPAIRMENTCHARGESRestructuringAndAssetImpairmentChargesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_41bfc4a2-0506-414e-aa18-e387bb4544a2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_d272a90c-6b24-4ef8-98cd-fd29c457e5ca" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_41bfc4a2-0506-414e-aa18-e387bb4544a2" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_d272a90c-6b24-4ef8-98cd-fd29c457e5ca" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis_006cd946-b37d-4beb-91a8-7f35c9d4e412" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringCostAndReserveAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_d272a90c-6b24-4ef8-98cd-fd29c457e5ca" xlink:to="loc_us-gaap_RestructuringCostAndReserveAxis_006cd946-b37d-4beb-91a8-7f35c9d4e412" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_006cd946-b37d-4beb-91a8-7f35c9d4e412_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TypeOfRestructuringDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_006cd946-b37d-4beb-91a8-7f35c9d4e412" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_006cd946-b37d-4beb-91a8-7f35c9d4e412_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_ad98ea01-4710-44e5-90fc-a2d9816a54fa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TypeOfRestructuringDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_006cd946-b37d-4beb-91a8-7f35c9d4e412" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_ad98ea01-4710-44e5-90fc-a2d9816a54fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeSeveranceMember_310e7c31-1267-4d3b-901e-a86ada9999df" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeSeveranceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_ad98ea01-4710-44e5-90fc-a2d9816a54fa" xlink:to="loc_us-gaap_EmployeeSeveranceMember_310e7c31-1267-4d3b-901e-a86ada9999df" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractTerminationMember_1af696b3-4612-452e-a966-71dd58a9b2b5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ContractTerminationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_ad98ea01-4710-44e5-90fc-a2d9816a54fa" xlink:to="loc_us-gaap_ContractTerminationMember_1af696b3-4612-452e-a966-71dd58a9b2b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_AssetImpairmentsMember_0455f461-03e7-4481-87af-c52df48556d2" xlink:href="enph-20240630.xsd#enph_AssetImpairmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_ad98ea01-4710-44e5-90fc-a2d9816a54fa" xlink:to="loc_enph_AssetImpairmentsMember_0455f461-03e7-4481-87af-c52df48556d2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_55bf61d3-839d-40f4-b102-34a121f836fc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_41bfc4a2-0506-414e-aa18-e387bb4544a2" xlink:to="loc_us-gaap_RestructuringCharges_55bf61d3-839d-40f4-b102-34a121f836fc" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/RESTRUCTURINGANDASSETIMPAIRMENTCHARGESRollforwardDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#RESTRUCTURINGANDASSETIMPAIRMENTCHARGESRollforwardDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/RESTRUCTURINGANDASSETIMPAIRMENTCHARGESRollforwardDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_fd0795a9-9607-4066-b4aa-45444e2338b0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_949b7efb-8946-4846-aa9c-b91d0baf977f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_fd0795a9-9607-4066-b4aa-45444e2338b0" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_949b7efb-8946-4846-aa9c-b91d0baf977f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis_53092550-6ff5-4d44-9218-dc21869ff871" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringCostAndReserveAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_949b7efb-8946-4846-aa9c-b91d0baf977f" xlink:to="loc_us-gaap_RestructuringCostAndReserveAxis_53092550-6ff5-4d44-9218-dc21869ff871" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_53092550-6ff5-4d44-9218-dc21869ff871_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TypeOfRestructuringDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_53092550-6ff5-4d44-9218-dc21869ff871" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_53092550-6ff5-4d44-9218-dc21869ff871_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_642cc3b3-0611-454f-b84d-8381486b9ac0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TypeOfRestructuringDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_53092550-6ff5-4d44-9218-dc21869ff871" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_642cc3b3-0611-454f-b84d-8381486b9ac0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeSeveranceMember_4bb3e86a-8e91-4c09-98c7-5e776496a3c6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeSeveranceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_642cc3b3-0611-454f-b84d-8381486b9ac0" xlink:to="loc_us-gaap_EmployeeSeveranceMember_4bb3e86a-8e91-4c09-98c7-5e776496a3c6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractTerminationMember_956c2671-daf4-49e7-8fb4-01da8c798d32" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ContractTerminationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_642cc3b3-0611-454f-b84d-8381486b9ac0" xlink:to="loc_us-gaap_ContractTerminationMember_956c2671-daf4-49e7-8fb4-01da8c798d32" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_AssetImpairmentsMember_f5fbb388-8ebd-409a-8edc-27a42ae2d7ff" xlink:href="enph-20240630.xsd#enph_AssetImpairmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_642cc3b3-0611-454f-b84d-8381486b9ac0" xlink:to="loc_enph_AssetImpairmentsMember_f5fbb388-8ebd-409a-8edc-27a42ae2d7ff" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanAxis_6b8b593e-71e4-4754-9e85-b9f95b08ebdb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringPlanAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_949b7efb-8946-4846-aa9c-b91d0baf977f" xlink:to="loc_us-gaap_RestructuringPlanAxis_6b8b593e-71e4-4754-9e85-b9f95b08ebdb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_6b8b593e-71e4-4754-9e85-b9f95b08ebdb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringPlanAxis_6b8b593e-71e4-4754-9e85-b9f95b08ebdb" xlink:to="loc_us-gaap_RestructuringPlanDomain_6b8b593e-71e4-4754-9e85-b9f95b08ebdb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_f5169774-195b-49b5-9a5c-2adb147205b3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringPlanAxis_6b8b593e-71e4-4754-9e85-b9f95b08ebdb" xlink:to="loc_us-gaap_RestructuringPlanDomain_f5169774-195b-49b5-9a5c-2adb147205b3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_A2023RestructuringPlanMember_b0fe3510-eea7-4bbb-aaf6-7181b27b016b" xlink:href="enph-20240630.xsd#enph_A2023RestructuringPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_f5169774-195b-49b5-9a5c-2adb147205b3" xlink:to="loc_enph_A2023RestructuringPlanMember_b0fe3510-eea7-4bbb-aaf6-7181b27b016b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveRollForward_1b477651-50ac-407d-a64f-b7d419f49ac6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringReserveRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_fd0795a9-9607-4066-b4aa-45444e2338b0" xlink:to="loc_us-gaap_RestructuringReserveRollForward_1b477651-50ac-407d-a64f-b7d419f49ac6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserve_bca01f95-a293-45fd-82a6-f06ecdd2fff4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringReserve"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_1b477651-50ac-407d-a64f-b7d419f49ac6" xlink:to="loc_us-gaap_RestructuringReserve_bca01f95-a293-45fd-82a6-f06ecdd2fff4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostsAndAssetImpairmentCharges_a1b4e66c-5c1c-46b9-8439-6d52fb3bd667" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringCostsAndAssetImpairmentCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_1b477651-50ac-407d-a64f-b7d419f49ac6" xlink:to="loc_us-gaap_RestructuringCostsAndAssetImpairmentCharges_a1b4e66c-5c1c-46b9-8439-6d52fb3bd667" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRestructuring_57932e06-4a1e-489f-9fac-494dbc1e1672" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsForRestructuring"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_1b477651-50ac-407d-a64f-b7d419f49ac6" xlink:to="loc_us-gaap_PaymentsForRestructuring_57932e06-4a1e-489f-9fac-494dbc1e1672" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveSettledWithoutCash2_735e1953-36cc-482b-87a1-b64fee2b9594" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringReserveSettledWithoutCash2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_1b477651-50ac-407d-a64f-b7d419f49ac6" xlink:to="loc_us-gaap_RestructuringReserveSettledWithoutCash2_735e1953-36cc-482b-87a1-b64fee2b9594" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserve_b5f915c7-fb99-4d29-9f9d-8ff5817c06ae" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringReserve"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/DEBTLongtermdebtDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#DEBTLongtermdebtDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/DEBTLongtermdebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_257e8250-bf3d-4936-944b-189e29e0740a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_1e87fd5f-663a-4065-9339-aedde74f8ada" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_257e8250-bf3d-4936-944b-189e29e0740a" xlink:to="loc_us-gaap_DebtInstrumentTable_1e87fd5f-663a-4065-9339-aedde74f8ada" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_652e079e-4823-45c5-8edc-1e35d8623fe3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_1e87fd5f-663a-4065-9339-aedde74f8ada" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_652e079e-4823-45c5-8edc-1e35d8623fe3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_652e079e-4823-45c5-8edc-1e35d8623fe3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_652e079e-4823-45c5-8edc-1e35d8623fe3" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_652e079e-4823-45c5-8edc-1e35d8623fe3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_e96b79ea-80a8-4265-8607-f8345c823ad7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_652e079e-4823-45c5-8edc-1e35d8623fe3" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_e96b79ea-80a8-4265-8607-f8345c823ad7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleNotesPayableMember_c1a59eb0-03f8-442c-b091-2d3bba369791" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConvertibleNotesPayableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_e96b79ea-80a8-4265-8607-f8345c823ad7" xlink:to="loc_us-gaap_ConvertibleNotesPayableMember_c1a59eb0-03f8-442c-b091-2d3bba369791" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_561b0ff7-e04e-414e-bcac-224433576b08" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_1e87fd5f-663a-4065-9339-aedde74f8ada" xlink:to="loc_us-gaap_DebtInstrumentAxis_561b0ff7-e04e-414e-bcac-224433576b08" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_561b0ff7-e04e-414e-bcac-224433576b08_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_561b0ff7-e04e-414e-bcac-224433576b08" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_561b0ff7-e04e-414e-bcac-224433576b08_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_10e6e8a9-4e43-4a5b-98db-9cefc1642859" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_561b0ff7-e04e-414e-bcac-224433576b08" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_10e6e8a9-4e43-4a5b-98db-9cefc1642859" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2028Member_8ebcaeb2-c15a-446c-9a9e-cdae59502199" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_10e6e8a9-4e43-4a5b-98db-9cefc1642859" xlink:to="loc_enph_ConvertibleSeniorNotesDue2028Member_8ebcaeb2-c15a-446c-9a9e-cdae59502199" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2026Member_9c705cb1-7e4a-43a8-aee3-9aa0ff687552" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_10e6e8a9-4e43-4a5b-98db-9cefc1642859" xlink:to="loc_enph_ConvertibleSeniorNotesDue2026Member_9c705cb1-7e4a-43a8-aee3-9aa0ff687552" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2025Member_253b9ded-fb90-45b9-a859-ab177ec6c0a4" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_10e6e8a9-4e43-4a5b-98db-9cefc1642859" xlink:to="loc_enph_ConvertibleSeniorNotesDue2025Member_253b9ded-fb90-45b9-a859-ab177ec6c0a4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_993525e9-c5ce-4822-858f-25ae088ee5cf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_257e8250-bf3d-4936-944b-189e29e0740a" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_993525e9-c5ce-4822-858f-25ae088ee5cf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_05672ac8-f152-4d26-bb9d-959d9db626ed" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_257e8250-bf3d-4936-944b-189e29e0740a" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_05672ac8-f152-4d26-bb9d-959d9db626ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscount_28d8e5cc-d243-4247-bcbd-3ac50b10c7b3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentUnamortizedDiscount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_257e8250-bf3d-4936-944b-189e29e0740a" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscount_28d8e5cc-d243-4247-bcbd-3ac50b10c7b3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_609344b5-6e11-4cec-bef4-6f92fe40a0bc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_257e8250-bf3d-4936-944b-189e29e0740a" xlink:to="loc_us-gaap_LongTermDebt_609344b5-6e11-4cec-bef4-6f92fe40a0bc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_4107dc4c-0d52-468e-abdb-b3cb2513aeb6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_257e8250-bf3d-4936-944b-189e29e0740a" xlink:to="loc_us-gaap_LongTermDebtCurrent_4107dc4c-0d52-468e-abdb-b3cb2513aeb6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_63a87374-0471-416a-a987-e37fd79799bc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_257e8250-bf3d-4936-944b-189e29e0740a" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_63a87374-0471-416a-a987-e37fd79799bc" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/DEBTScheduleofInterestCostRecognizedInStatementsOfOperationsDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#DEBTScheduleofInterestCostRecognizedInStatementsOfOperationsDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/DEBTScheduleofInterestCostRecognizedInStatementsOfOperationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_ad05c540-a174-44f7-a002-733aca1ca0b8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_34408475-cbba-408a-8720-42c78f42b0a1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ad05c540-a174-44f7-a002-733aca1ca0b8" xlink:to="loc_us-gaap_DebtInstrumentTable_34408475-cbba-408a-8720-42c78f42b0a1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_ee5fdeeb-8063-4ec5-94be-e6a0cbd07586" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_34408475-cbba-408a-8720-42c78f42b0a1" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_ee5fdeeb-8063-4ec5-94be-e6a0cbd07586" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_ee5fdeeb-8063-4ec5-94be-e6a0cbd07586_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_ee5fdeeb-8063-4ec5-94be-e6a0cbd07586" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_ee5fdeeb-8063-4ec5-94be-e6a0cbd07586_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_1b4e2e46-fec4-47c5-9b6a-cf2b0d6f96a4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_ee5fdeeb-8063-4ec5-94be-e6a0cbd07586" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_1b4e2e46-fec4-47c5-9b6a-cf2b0d6f96a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleNotesPayableMember_c492af69-0a23-4a60-ba60-0d98e39f38fe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConvertibleNotesPayableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_1b4e2e46-fec4-47c5-9b6a-cf2b0d6f96a4" xlink:to="loc_us-gaap_ConvertibleNotesPayableMember_c492af69-0a23-4a60-ba60-0d98e39f38fe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_2a60893e-99fb-4f9a-8157-dd55f9f05734" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_34408475-cbba-408a-8720-42c78f42b0a1" xlink:to="loc_us-gaap_DebtInstrumentAxis_2a60893e-99fb-4f9a-8157-dd55f9f05734" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_2a60893e-99fb-4f9a-8157-dd55f9f05734_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_2a60893e-99fb-4f9a-8157-dd55f9f05734" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_2a60893e-99fb-4f9a-8157-dd55f9f05734_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_239a0716-8784-49a5-8ecf-e20c01a9da6a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_2a60893e-99fb-4f9a-8157-dd55f9f05734" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_239a0716-8784-49a5-8ecf-e20c01a9da6a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2028Member_33af0297-ad0e-45de-896b-32f77cd64bdc" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_239a0716-8784-49a5-8ecf-e20c01a9da6a" xlink:to="loc_enph_ConvertibleSeniorNotesDue2028Member_33af0297-ad0e-45de-896b-32f77cd64bdc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2026Member_a13fbe18-49a5-45bf-9258-c6c340f40330" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_239a0716-8784-49a5-8ecf-e20c01a9da6a" xlink:to="loc_enph_ConvertibleSeniorNotesDue2026Member_a13fbe18-49a5-45bf-9258-c6c340f40330" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2025Member_58197267-55c9-41b8-8196-e96cb1fda960" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_239a0716-8784-49a5-8ecf-e20c01a9da6a" xlink:to="loc_enph_ConvertibleSeniorNotesDue2025Member_58197267-55c9-41b8-8196-e96cb1fda960" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2023Member_0c110f58-578d-46c5-b477-8c82be9152c5" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2023Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_239a0716-8784-49a5-8ecf-e20c01a9da6a" xlink:to="loc_enph_ConvertibleSeniorNotesDue2023Member_0c110f58-578d-46c5-b477-8c82be9152c5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebtExcludingAmortization_ff6cd037-4c28-4b6a-891a-326ad9c259bc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestExpenseDebtExcludingAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ad05c540-a174-44f7-a002-733aca1ca0b8" xlink:to="loc_us-gaap_InterestExpenseDebtExcludingAmortization_ff6cd037-4c28-4b6a-891a-326ad9c259bc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfDebtDiscountPremium_13347088-7cca-442b-ab37-1b1314bffb6b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AmortizationOfDebtDiscountPremium"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ad05c540-a174-44f7-a002-733aca1ca0b8" xlink:to="loc_us-gaap_AmortizationOfDebtDiscountPremium_13347088-7cca-442b-ab37-1b1314bffb6b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts_3859f1f6-83e1-4e04-bfca-907de253ccbc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AmortizationOfFinancingCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ad05c540-a174-44f7-a002-733aca1ca0b8" xlink:to="loc_us-gaap_AmortizationOfFinancingCosts_3859f1f6-83e1-4e04-bfca-907de253ccbc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebt_ef185485-f8e4-4bdf-a00f-2813155f55c9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestExpenseDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ad05c540-a174-44f7-a002-733aca1ca0b8" xlink:to="loc_us-gaap_InterestExpenseDebt_ef185485-f8e4-4bdf-a00f-2813155f55c9" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/DEBTConvertibleSeniorNotesduein2028NarrativeDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#DEBTConvertibleSeniorNotesduein2028NarrativeDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/DEBTConvertibleSeniorNotesduein2028NarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_363a802e-e170-45f2-b022-feb255b616e9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:to="loc_us-gaap_DebtInstrumentTable_363a802e-e170-45f2-b022-feb255b616e9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_ba8c07db-3f11-44a2-af0d-e939473775ca" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_363a802e-e170-45f2-b022-feb255b616e9" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_ba8c07db-3f11-44a2-af0d-e939473775ca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_ba8c07db-3f11-44a2-af0d-e939473775ca_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_ba8c07db-3f11-44a2-af0d-e939473775ca" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_ba8c07db-3f11-44a2-af0d-e939473775ca_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_2e605530-5565-4d70-8624-02b6c48c9d5a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_ba8c07db-3f11-44a2-af0d-e939473775ca" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_2e605530-5565-4d70-8624-02b6c48c9d5a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodOneMember_46461bf4-e344-4f05-9431-19b91797c0a1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_2e605530-5565-4d70-8624-02b6c48c9d5a" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodOneMember_46461bf4-e344-4f05-9431-19b91797c0a1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodTwoMember_28e08c07-9f76-4d09-946c-0ed4626a6445" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_2e605530-5565-4d70-8624-02b6c48c9d5a" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodTwoMember_28e08c07-9f76-4d09-946c-0ed4626a6445" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_3eaf5c7f-4b1e-448c-8f1f-69c4a1b6ca39" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_363a802e-e170-45f2-b022-feb255b616e9" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_3eaf5c7f-4b1e-448c-8f1f-69c4a1b6ca39" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_3eaf5c7f-4b1e-448c-8f1f-69c4a1b6ca39_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_3eaf5c7f-4b1e-448c-8f1f-69c4a1b6ca39" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_3eaf5c7f-4b1e-448c-8f1f-69c4a1b6ca39_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_3ee87d0a-9e73-4e7f-bef6-a7666a6135d2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_3eaf5c7f-4b1e-448c-8f1f-69c4a1b6ca39" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_3ee87d0a-9e73-4e7f-bef6-a7666a6135d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleNotesPayableMember_94dcb4c2-fc96-4afb-935b-b928ffeb88bd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConvertibleNotesPayableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_3ee87d0a-9e73-4e7f-bef6-a7666a6135d2" xlink:to="loc_us-gaap_ConvertibleNotesPayableMember_94dcb4c2-fc96-4afb-935b-b928ffeb88bd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_31dd35ae-48e1-4dba-b060-4ab4b25b3e10" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_363a802e-e170-45f2-b022-feb255b616e9" xlink:to="loc_us-gaap_DebtInstrumentAxis_31dd35ae-48e1-4dba-b060-4ab4b25b3e10" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_31dd35ae-48e1-4dba-b060-4ab4b25b3e10_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_31dd35ae-48e1-4dba-b060-4ab4b25b3e10" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_31dd35ae-48e1-4dba-b060-4ab4b25b3e10_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_9de6bf13-7b81-4d3c-a592-7c57f8b2090f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_31dd35ae-48e1-4dba-b060-4ab4b25b3e10" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_9de6bf13-7b81-4d3c-a592-7c57f8b2090f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2028Member_f2611ae0-4f67-45b2-b46d-c7cf0f7e2483" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_9de6bf13-7b81-4d3c-a592-7c57f8b2090f" xlink:to="loc_enph_ConvertibleSeniorNotesDue2028Member_f2611ae0-4f67-45b2-b46d-c7cf0f7e2483" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_a426e217-973c-4f35-b2bc-cc87bd89b231" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_a426e217-973c-4f35-b2bc-cc87bd89b231" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_eb2794a6-cb6a-404b-8a8b-f93c1934936d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_eb2794a6-cb6a-404b-8a8b-f93c1934936d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromConvertibleDebt_1ebeda7a-66ce-4d68-8cb6-0539954e2164" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromConvertibleDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:to="loc_us-gaap_ProceedsFromConvertibleDebt_1ebeda7a-66ce-4d68-8cb6-0539954e2164" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleConversionRatio1_1ef847a2-961f-478f-82d4-97fc290b11d3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleConversionRatio1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:to="loc_us-gaap_DebtInstrumentConvertibleConversionRatio1_1ef847a2-961f-478f-82d4-97fc290b11d3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_9d544122-83d1-48f2-a6da-6319ade1dd3e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleConversionPrice1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:to="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_9d544122-83d1-48f2-a6da-6319ade1dd3e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger_67197fa6-7a8f-463c-8cce-c8faf7e4edae" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:to="loc_us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger_67197fa6-7a8f-463c-8cce-c8faf7e4edae" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleStockPriceTrigger_38e23c04-0d27-40ac-8f1d-7117f9f3ada4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleStockPriceTrigger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:to="loc_us-gaap_DebtInstrumentConvertibleStockPriceTrigger_38e23c04-0d27-40ac-8f1d-7117f9f3ada4" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleThresholdTradingDays_d80eccd1-b52c-401c-a909-af6f0fbc1d9b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleThresholdTradingDays"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:to="loc_us-gaap_DebtInstrumentConvertibleThresholdTradingDays_d80eccd1-b52c-401c-a909-af6f0fbc1d9b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1_f29ee917-9596-4e44-9347-fd98adabdb1c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:to="loc_us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1_f29ee917-9596-4e44-9347-fd98adabdb1c" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_DebtInstrumentConvertibleBusinessDayPeriodAfterMeasurementPeriod_9e1de5d3-0bd2-41a8-9411-7a23f00f17d9" xlink:href="enph-20240630.xsd#enph_DebtInstrumentConvertibleBusinessDayPeriodAfterMeasurementPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:to="loc_enph_DebtInstrumentConvertibleBusinessDayPeriodAfterMeasurementPeriod_9e1de5d3-0bd2-41a8-9411-7a23f00f17d9" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_DebtInstrumentConvertibleMeasurementPeriodPercentageOfStockPriceTrigger_6f6ba0cb-d641-4af5-b541-8b062e0a0cbb" xlink:href="enph-20240630.xsd#enph_DebtInstrumentConvertibleMeasurementPeriodPercentageOfStockPriceTrigger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:to="loc_enph_DebtInstrumentConvertibleMeasurementPeriodPercentageOfStockPriceTrigger_6f6ba0cb-d641-4af5-b541-8b062e0a0cbb" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_e93a6bfc-7af1-4dd1-8311-d49e978fac4d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_e93a6bfc-7af1-4dd1-8311-d49e978fac4d" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_DebtInstrumentConvertibleConversionShares_7f52b5b3-709e-438c-9d27-edb7f42a3954" xlink:href="enph-20240630.xsd#enph_DebtInstrumentConvertibleConversionShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:to="loc_enph_DebtInstrumentConvertibleConversionShares_7f52b5b3-709e-438c-9d27-edb7f42a3954" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForHedgeFinancingActivities_c323df14-2961-472c-9ac2-8900f2acedf2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsForHedgeFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:to="loc_us-gaap_PaymentsForHedgeFinancingActivities_c323df14-2961-472c-9ac2-8900f2acedf2" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_c35fa64c-7525-44b6-811b-8030b5e65142" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_c35fa64c-7525-44b6-811b-8030b5e65142" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfWarrants_fcd65f84-1a75-4eaa-8fde-7fce6f89c01e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromIssuanceOfWarrants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_27260240-99c9-4e63-82f3-22ec303f3baf" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfWarrants_fcd65f84-1a75-4eaa-8fde-7fce6f89c01e" xlink:type="arc" order="15"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/DEBTConvertibleSeniorNotesduein2026NarrativeDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#DEBTConvertibleSeniorNotesduein2026NarrativeDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/DEBTConvertibleSeniorNotesduein2026NarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_dc6c25b2-145d-4d4f-a783-f1e6ca1b1d69" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:to="loc_us-gaap_DebtInstrumentTable_dc6c25b2-145d-4d4f-a783-f1e6ca1b1d69" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_6fed7aac-b22d-498b-968d-5008b09d8d14" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_dc6c25b2-145d-4d4f-a783-f1e6ca1b1d69" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_6fed7aac-b22d-498b-968d-5008b09d8d14" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_6fed7aac-b22d-498b-968d-5008b09d8d14_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_6fed7aac-b22d-498b-968d-5008b09d8d14" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_6fed7aac-b22d-498b-968d-5008b09d8d14_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_32308b02-0ae2-4fb6-8320-2085755a6d12" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_6fed7aac-b22d-498b-968d-5008b09d8d14" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_32308b02-0ae2-4fb6-8320-2085755a6d12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodOneMember_14741849-7fbd-4882-ba05-243a2eb6135c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_32308b02-0ae2-4fb6-8320-2085755a6d12" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodOneMember_14741849-7fbd-4882-ba05-243a2eb6135c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodTwoMember_1c33141f-0e64-4789-bd3a-a5943b060c1f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_32308b02-0ae2-4fb6-8320-2085755a6d12" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodTwoMember_1c33141f-0e64-4789-bd3a-a5943b060c1f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_90135e25-be89-4e86-b6f7-7241c4dcfbba" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_dc6c25b2-145d-4d4f-a783-f1e6ca1b1d69" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_90135e25-be89-4e86-b6f7-7241c4dcfbba" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_90135e25-be89-4e86-b6f7-7241c4dcfbba_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_90135e25-be89-4e86-b6f7-7241c4dcfbba" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_90135e25-be89-4e86-b6f7-7241c4dcfbba_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_81d6f1cb-6829-4cf4-8637-4b19db1bc396" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_90135e25-be89-4e86-b6f7-7241c4dcfbba" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_81d6f1cb-6829-4cf4-8637-4b19db1bc396" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleNotesPayableMember_993fb871-fbbd-4c40-826c-649f377c9a7a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConvertibleNotesPayableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_81d6f1cb-6829-4cf4-8637-4b19db1bc396" xlink:to="loc_us-gaap_ConvertibleNotesPayableMember_993fb871-fbbd-4c40-826c-649f377c9a7a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_2d11a4c7-327c-4eff-a3cd-cd39c20bf62f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_dc6c25b2-145d-4d4f-a783-f1e6ca1b1d69" xlink:to="loc_us-gaap_DebtInstrumentAxis_2d11a4c7-327c-4eff-a3cd-cd39c20bf62f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_2d11a4c7-327c-4eff-a3cd-cd39c20bf62f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_2d11a4c7-327c-4eff-a3cd-cd39c20bf62f" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_2d11a4c7-327c-4eff-a3cd-cd39c20bf62f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_c0ecccef-87f5-48f5-b3b3-f45b701ea6c2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_2d11a4c7-327c-4eff-a3cd-cd39c20bf62f" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_c0ecccef-87f5-48f5-b3b3-f45b701ea6c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2026Member_794eda89-bc5e-4f49-8c9b-e2099728ccdf" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c0ecccef-87f5-48f5-b3b3-f45b701ea6c2" xlink:to="loc_enph_ConvertibleSeniorNotesDue2026Member_794eda89-bc5e-4f49-8c9b-e2099728ccdf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_f5fbd5a6-2ba0-4d28-a4c6-fd5c01861619" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_f5fbd5a6-2ba0-4d28-a4c6-fd5c01861619" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_901c68b9-ae87-454c-8980-ce4383b22e49" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_901c68b9-ae87-454c-8980-ce4383b22e49" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromConvertibleDebt_f74d36ba-a4eb-4a45-a7b4-e30c156b65ee" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromConvertibleDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:to="loc_us-gaap_ProceedsFromConvertibleDebt_f74d36ba-a4eb-4a45-a7b4-e30c156b65ee" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleConversionRatio1_6d2ed541-4c27-41e4-8d5d-5200113cc564" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleConversionRatio1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:to="loc_us-gaap_DebtInstrumentConvertibleConversionRatio1_6d2ed541-4c27-41e4-8d5d-5200113cc564" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_ea2c990b-3ed7-44ec-a82e-ecb6678da7be" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleConversionPrice1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:to="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_ea2c990b-3ed7-44ec-a82e-ecb6678da7be" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger_aa8273ee-ef7b-41a5-9728-f4467d4b7cbb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:to="loc_us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger_aa8273ee-ef7b-41a5-9728-f4467d4b7cbb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleStockPriceTrigger_0c8ae27a-08d1-4273-ad9c-ad5698ef9b02" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleStockPriceTrigger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:to="loc_us-gaap_DebtInstrumentConvertibleStockPriceTrigger_0c8ae27a-08d1-4273-ad9c-ad5698ef9b02" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleThresholdTradingDays_dfb8b31e-9572-49a7-b3a9-44df8cb264d3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleThresholdTradingDays"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:to="loc_us-gaap_DebtInstrumentConvertibleThresholdTradingDays_dfb8b31e-9572-49a7-b3a9-44df8cb264d3" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1_93b21ac2-d790-4d63-ba68-ea0658f89f8b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:to="loc_us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1_93b21ac2-d790-4d63-ba68-ea0658f89f8b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_DebtInstrumentConvertibleBusinessDayPeriodAfterMeasurementPeriod_86b94fa1-4bce-4e98-92ef-cd474e17ffdf" xlink:href="enph-20240630.xsd#enph_DebtInstrumentConvertibleBusinessDayPeriodAfterMeasurementPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:to="loc_enph_DebtInstrumentConvertibleBusinessDayPeriodAfterMeasurementPeriod_86b94fa1-4bce-4e98-92ef-cd474e17ffdf" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_DebtInstrumentConvertibleMeasurementPeriodPercentageOfStockPriceTrigger_fa1c36c7-856b-442f-8bf6-e1a557a8a64d" xlink:href="enph-20240630.xsd#enph_DebtInstrumentConvertibleMeasurementPeriodPercentageOfStockPriceTrigger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:to="loc_enph_DebtInstrumentConvertibleMeasurementPeriodPercentageOfStockPriceTrigger_fa1c36c7-856b-442f-8bf6-e1a557a8a64d" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_2ddb3210-c8eb-402b-b929-194bf3995f38" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_2ddb3210-c8eb-402b-b929-194bf3995f38" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_DebtInstrumentConvertibleConversionShares_4b8bfdc5-45bd-48ca-90a7-fd4c32f89dce" xlink:href="enph-20240630.xsd#enph_DebtInstrumentConvertibleConversionShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:to="loc_enph_DebtInstrumentConvertibleConversionShares_4b8bfdc5-45bd-48ca-90a7-fd4c32f89dce" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForHedgeFinancingActivities_0c28ffe0-1c02-4aac-9a35-879771e361f7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsForHedgeFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:to="loc_us-gaap_PaymentsForHedgeFinancingActivities_0c28ffe0-1c02-4aac-9a35-879771e361f7" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_760ebbd3-1bbb-4d9b-a2a2-d2542a83d96e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_760ebbd3-1bbb-4d9b-a2a2-d2542a83d96e" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfWarrants_a77628c9-c22a-48e3-95f5-ef8b85f5069a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromIssuanceOfWarrants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1b3a5d0f-63a5-4ec4-8b1c-70b2a607ffa9" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfWarrants_a77628c9-c22a-48e3-95f5-ef8b85f5069a" xlink:type="arc" order="15"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/DEBTConvertibleSeniorNotesduein2025NarrativeDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#DEBTConvertibleSeniorNotesduein2025NarrativeDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/DEBTConvertibleSeniorNotesduein2025NarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_cc3cdc59-fde2-4d80-8e42-eb36859cff61" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_DebtInstrumentTable_cc3cdc59-fde2-4d80-8e42-eb36859cff61" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_c79e758a-73ff-4eaa-b77a-ea7d574b060a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_cc3cdc59-fde2-4d80-8e42-eb36859cff61" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_c79e758a-73ff-4eaa-b77a-ea7d574b060a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_c79e758a-73ff-4eaa-b77a-ea7d574b060a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_c79e758a-73ff-4eaa-b77a-ea7d574b060a" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_c79e758a-73ff-4eaa-b77a-ea7d574b060a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_1361576a-3c42-4507-a47c-9dd070692283" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_c79e758a-73ff-4eaa-b77a-ea7d574b060a" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_1361576a-3c42-4507-a47c-9dd070692283" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodOneMember_40cd72e6-9e37-4f41-a75f-93756601ee08" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_1361576a-3c42-4507-a47c-9dd070692283" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodOneMember_40cd72e6-9e37-4f41-a75f-93756601ee08" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodTwoMember_404484c2-d5f2-4c2c-94bf-f342ef6e2717" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_1361576a-3c42-4507-a47c-9dd070692283" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodTwoMember_404484c2-d5f2-4c2c-94bf-f342ef6e2717" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_3ed8d3e9-d683-4900-ba3e-08b9ceb089d2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_cc3cdc59-fde2-4d80-8e42-eb36859cff61" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_3ed8d3e9-d683-4900-ba3e-08b9ceb089d2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_3ed8d3e9-d683-4900-ba3e-08b9ceb089d2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_3ed8d3e9-d683-4900-ba3e-08b9ceb089d2" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_3ed8d3e9-d683-4900-ba3e-08b9ceb089d2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_aae3ec46-717d-4f7f-b3a3-ef980655471e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_3ed8d3e9-d683-4900-ba3e-08b9ceb089d2" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_aae3ec46-717d-4f7f-b3a3-ef980655471e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleNotesPayableMember_7347ab8e-e94a-4a67-8124-6e2be348b593" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConvertibleNotesPayableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_aae3ec46-717d-4f7f-b3a3-ef980655471e" xlink:to="loc_us-gaap_ConvertibleNotesPayableMember_7347ab8e-e94a-4a67-8124-6e2be348b593" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_c6bbecfd-8f25-43f4-bed9-84137259c4be" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_cc3cdc59-fde2-4d80-8e42-eb36859cff61" xlink:to="loc_us-gaap_DebtInstrumentAxis_c6bbecfd-8f25-43f4-bed9-84137259c4be" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_c6bbecfd-8f25-43f4-bed9-84137259c4be_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_c6bbecfd-8f25-43f4-bed9-84137259c4be" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_c6bbecfd-8f25-43f4-bed9-84137259c4be_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_9f23ba16-e9c7-4fa7-94f6-88fcaeec3960" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_c6bbecfd-8f25-43f4-bed9-84137259c4be" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_9f23ba16-e9c7-4fa7-94f6-88fcaeec3960" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2025Member_bc774f47-3373-4d2e-bc46-6d3ef026ca90" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_9f23ba16-e9c7-4fa7-94f6-88fcaeec3960" xlink:to="loc_enph_ConvertibleSeniorNotesDue2025Member_bc774f47-3373-4d2e-bc46-6d3ef026ca90" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_859ceaea-d4ad-4015-ba03-05f2c123ad8e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_859ceaea-d4ad-4015-ba03-05f2c123ad8e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_00ef1665-5665-46d4-b466-0803fdedb977" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_00ef1665-5665-46d4-b466-0803fdedb977" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_dfa5ef15-dc00-4b3e-a275-4036f0fd0da9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleConversionPrice1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_dfa5ef15-dc00-4b3e-a275-4036f0fd0da9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleConversionRatio1_b8e39eee-7d30-45e2-be5b-c4feab3d9a21" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleConversionRatio1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_DebtInstrumentConvertibleConversionRatio1_b8e39eee-7d30-45e2-be5b-c4feab3d9a21" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromConvertibleDebt_e181fe11-68dd-41e3-b610-6901560fd96a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromConvertibleDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_ProceedsFromConvertibleDebt_e181fe11-68dd-41e3-b610-6901560fd96a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleThresholdTradingDays_df8c5a1e-46a5-4797-8c3a-38a690ce9fa6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleThresholdTradingDays"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_DebtInstrumentConvertibleThresholdTradingDays_df8c5a1e-46a5-4797-8c3a-38a690ce9fa6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1_5d94e2fa-784b-464c-84f7-a80f3859d1ad" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1_5d94e2fa-784b-464c-84f7-a80f3859d1ad" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger_6b977705-6b60-4a9f-a882-d3cb86e19941" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger_6b977705-6b60-4a9f-a882-d3cb86e19941" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_DebtInstrumentConvertibleBusinessDayPeriodAfterMeasurementPeriod_435261aa-8f12-49c5-a165-f805f17e934b" xlink:href="enph-20240630.xsd#enph_DebtInstrumentConvertibleBusinessDayPeriodAfterMeasurementPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_enph_DebtInstrumentConvertibleBusinessDayPeriodAfterMeasurementPeriod_435261aa-8f12-49c5-a165-f805f17e934b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_DebtInstrumentConvertibleMeasurementPeriodPercentageOfStockPriceTrigger_95a02df3-9772-4e5f-8c2f-a593eb1da1a2" xlink:href="enph-20240630.xsd#enph_DebtInstrumentConvertibleMeasurementPeriodPercentageOfStockPriceTrigger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_enph_DebtInstrumentConvertibleMeasurementPeriodPercentageOfStockPriceTrigger_95a02df3-9772-4e5f-8c2f-a593eb1da1a2" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleStockPriceTrigger_6d5edf84-4318-4bac-9b6c-da3dc0cd6a67" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentConvertibleStockPriceTrigger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_DebtInstrumentConvertibleStockPriceTrigger_6d5edf84-4318-4bac-9b6c-da3dc0cd6a67" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_0d11fc3b-47c5-4a2a-990f-c66fd425bdd9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_LongTermDebt_0d11fc3b-47c5-4a2a-990f-c66fd425bdd9" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtConversionConvertedInstrumentAmount1_c883f398-d3a8-48be-9b15-816b7e86b4c4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtConversionConvertedInstrumentAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_DebtConversionConvertedInstrumentAmount1_c883f398-d3a8-48be-9b15-816b7e86b4c4" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_3b239847-672c-491f-b2f2-5c52d2477428" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_3b239847-672c-491f-b2f2-5c52d2477428" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities_023eaed7-56a1-4e2c-a4a0-67ed3e0341db" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities_023eaed7-56a1-4e2c-a4a0-67ed3e0341db" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConversionOfConvertibleSecuritiesOffsetByNotesHedge_74ebbbe9-4cf3-4428-9954-ab74f0c9a098" xlink:href="enph-20240630.xsd#enph_ConversionOfConvertibleSecuritiesOffsetByNotesHedge"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_enph_ConversionOfConvertibleSecuritiesOffsetByNotesHedge_74ebbbe9-4cf3-4428-9954-ab74f0c9a098" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_f21d8a19-da11-4a33-968b-09d38ab7e950" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_LongTermDebtCurrent_f21d8a19-da11-4a33-968b-09d38ab7e950" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_4c4b2ef2-145d-40c2-9e22-4daa267e6fcf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_4c4b2ef2-145d-40c2-9e22-4daa267e6fcf" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscount_4b2f2880-a2df-4db5-9247-b4f81ff60889" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentUnamortizedDiscount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscount_4b2f2880-a2df-4db5-9247-b4f81ff60889" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_DebtInstrumentRemainingDiscountAmortizationPeriod_f54ad4d9-4f42-443a-8c64-052b50c41a04" xlink:href="enph-20240630.xsd#enph_DebtInstrumentRemainingDiscountAmortizationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_enph_DebtInstrumentRemainingDiscountAmortizationPeriod_f54ad4d9-4f42-443a-8c64-052b50c41a04" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_DebtInstrumentConvertibleConversionShares_309dc070-36bf-4971-a5cd-8acb3134ce65" xlink:href="enph-20240630.xsd#enph_DebtInstrumentConvertibleConversionShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_enph_DebtInstrumentConvertibleConversionShares_309dc070-36bf-4971-a5cd-8acb3134ce65" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForHedgeFinancingActivities_5a5e8256-a04d-4a89-8895-a2248b26c3b9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsForHedgeFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_PaymentsForHedgeFinancingActivities_5a5e8256-a04d-4a89-8895-a2248b26c3b9" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_933cd9bf-4a98-44cf-ba9c-001e637a7526" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_933cd9bf-4a98-44cf-ba9c-001e637a7526" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfWarrants_902cfe61-1f75-4baf-97d1-58853333b1e0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromIssuanceOfWarrants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfWarrants_902cfe61-1f75-4baf-97d1-58853333b1e0" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleNotesHedgeTransactionOptionsOutstanding_516625c7-daa2-48d1-86a3-a4344037fa80" xlink:href="enph-20240630.xsd#enph_ConvertibleNotesHedgeTransactionOptionsOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_enph_ConvertibleNotesHedgeTransactionOptionsOutstanding_516625c7-daa2-48d1-86a3-a4344037fa80" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightOutstanding_5f0db801-bbbb-4434-8cee-5e4bf90fb34f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfWarrantOrRightOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_49aef9ea-404a-432d-9946-07139f703afd" xlink:to="loc_us-gaap_ClassOfWarrantOrRightOutstanding_5f0db801-bbbb-4434-8cee-5e4bf90fb34f" xlink:type="arc" order="25"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/STOCKHOLDERSEQUITYDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#STOCKHOLDERSEQUITYDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/STOCKHOLDERSEQUITYDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityClassOfTreasuryStockLineItems_a0b07ec6-1b08-4b14-994c-6b1e2b94c5c3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityClassOfTreasuryStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfTreasuryStockTable_d3283a24-b0b2-4218-b311-158260149afc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfTreasuryStockTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_a0b07ec6-1b08-4b14-994c-6b1e2b94c5c3" xlink:to="loc_us-gaap_ClassOfTreasuryStockTable_d3283a24-b0b2-4218-b311-158260149afc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramAxis_a962ff97-8b94-4a7a-ae88-a599fe00bd21" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ShareRepurchaseProgramAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ClassOfTreasuryStockTable_d3283a24-b0b2-4218-b311-158260149afc" xlink:to="loc_srt_ShareRepurchaseProgramAxis_a962ff97-8b94-4a7a-ae88-a599fe00bd21" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_a962ff97-8b94-4a7a-ae88-a599fe00bd21_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ShareRepurchaseProgramAxis_a962ff97-8b94-4a7a-ae88-a599fe00bd21" xlink:to="loc_srt_ShareRepurchaseProgramDomain_a962ff97-8b94-4a7a-ae88-a599fe00bd21_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_462ef692-37f2-4b7f-87f9-9fbe5d06f260" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ShareRepurchaseProgramAxis_a962ff97-8b94-4a7a-ae88-a599fe00bd21" xlink:to="loc_srt_ShareRepurchaseProgramDomain_462ef692-37f2-4b7f-87f9-9fbe5d06f260" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_A2023RepurchaseProgramMember_5b965d0b-453c-4274-8da6-acdeee9446c8" xlink:href="enph-20240630.xsd#enph_A2023RepurchaseProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_462ef692-37f2-4b7f-87f9-9fbe5d06f260" xlink:to="loc_enph_A2023RepurchaseProgramMember_5b965d0b-453c-4274-8da6-acdeee9446c8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramAuthorizedAmount1_0a18309e-3475-4cde-a386-411deb34d51e" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_a0b07ec6-1b08-4b14-994c-6b1e2b94c5c3" xlink:to="loc_srt_StockRepurchaseProgramAuthorizedAmount1_0a18309e-3475-4cde-a386-411deb34d51e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_eec8a9a7-c314-4d40-b588-c630028e92ee" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_a0b07ec6-1b08-4b14-994c-6b1e2b94c5c3" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_eec8a9a7-c314-4d40-b588-c630028e92ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_c3e82b32-8bf2-4f90-b359-4e1f7e3470c7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TreasuryStockAcquiredAverageCostPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_a0b07ec6-1b08-4b14-994c-6b1e2b94c5c3" xlink:to="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_c3e82b32-8bf2-4f90-b359-4e1f7e3470c7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_da93084d-a77f-4cc5-ba8c-2913ea799244" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_a0b07ec6-1b08-4b14-994c-6b1e2b94c5c3" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_da93084d-a77f-4cc5-ba8c-2913ea799244" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_0118e5b9-546d-4089-8143-df273add4f9f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_a0b07ec6-1b08-4b14-994c-6b1e2b94c5c3" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_0118e5b9-546d-4089-8143-df273add4f9f" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/STOCKBASEDCOMPENSATIONSummaryofStockbasedCompensationExpenseDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#STOCKBASEDCOMPENSATIONSummaryofStockbasedCompensationExpenseDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/STOCKBASEDCOMPENSATIONSummaryofStockbasedCompensationExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_fb1b093c-8afb-4a5a-b71d-964d6db73523" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_723ca283-53d9-48c9-9604-cbb21e3ddd80" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_fb1b093c-8afb-4a5a-b71d-964d6db73523" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_723ca283-53d9-48c9-9604-cbb21e3ddd80" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_66a59f87-fd54-48e4-b3c9-3d9683ec7ea4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_723ca283-53d9-48c9-9604-cbb21e3ddd80" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_66a59f87-fd54-48e4-b3c9-3d9683ec7ea4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_66a59f87-fd54-48e4-b3c9-3d9683ec7ea4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_66a59f87-fd54-48e4-b3c9-3d9683ec7ea4" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_66a59f87-fd54-48e4-b3c9-3d9683ec7ea4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_8afae072-eed6-43b3-8373-c6a1b8e1dd86" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_66a59f87-fd54-48e4-b3c9-3d9683ec7ea4" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_8afae072-eed6-43b3-8373-c6a1b8e1dd86" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_c0b38906-a861-4a84-b9d1-368bc0e1bc71" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_8afae072-eed6-43b3-8373-c6a1b8e1dd86" xlink:to="loc_us-gaap_CostOfSalesMember_c0b38906-a861-4a84-b9d1-368bc0e1bc71" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseMember_bb5973b9-83c5-4c1c-9fc5-58d84519bba2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ResearchAndDevelopmentExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_8afae072-eed6-43b3-8373-c6a1b8e1dd86" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseMember_bb5973b9-83c5-4c1c-9fc5-58d84519bba2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpenseMember_7a7eb32a-33d6-4e80-a323-3d60581f0ba0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SellingAndMarketingExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_8afae072-eed6-43b3-8373-c6a1b8e1dd86" xlink:to="loc_us-gaap_SellingAndMarketingExpenseMember_7a7eb32a-33d6-4e80-a323-3d60581f0ba0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_eaef93c7-4376-49a6-9d88-96dd353a4891" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeneralAndAdministrativeExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_8afae072-eed6-43b3-8373-c6a1b8e1dd86" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_eaef93c7-4376-49a6-9d88-96dd353a4891" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_bf1e2c24-f18c-40b9-9390-5625f0590f4d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_fb1b093c-8afb-4a5a-b71d-964d6db73523" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_bf1e2c24-f18c-40b9-9390-5625f0590f4d" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/STOCKBASEDCOMPENSATIONSummaryofStockBasedCompensationExpenseAssociatedwithEachTypeofAwardDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#STOCKBASEDCOMPENSATIONSummaryofStockBasedCompensationExpenseAssociatedwithEachTypeofAwardDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/STOCKBASEDCOMPENSATIONSummaryofStockBasedCompensationExpenseAssociatedwithEachTypeofAwardDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b5304709-e277-428d-8e36-f3dc8fd479a6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_b2f1b934-e803-4d7a-9ea7-8efd1dd7d18e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b5304709-e277-428d-8e36-f3dc8fd479a6" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_b2f1b934-e803-4d7a-9ea7-8efd1dd7d18e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_6b35567c-b324-47ca-bef8-342383ed447d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_b2f1b934-e803-4d7a-9ea7-8efd1dd7d18e" xlink:to="loc_us-gaap_AwardTypeAxis_6b35567c-b324-47ca-bef8-342383ed447d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6b35567c-b324-47ca-bef8-342383ed447d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_6b35567c-b324-47ca-bef8-342383ed447d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6b35567c-b324-47ca-bef8-342383ed447d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8e8a6123-125e-4628-ba03-b9c76d90d81f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_6b35567c-b324-47ca-bef8-342383ed447d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8e8a6123-125e-4628-ba03-b9c76d90d81f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_EmployeeStockOptionsAndRestrictedStockUnitsMember_f474a28c-fcc7-407b-b4e7-27d227cf7282" xlink:href="enph-20240630.xsd#enph_EmployeeStockOptionsAndRestrictedStockUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8e8a6123-125e-4628-ba03-b9c76d90d81f" xlink:to="loc_enph_EmployeeStockOptionsAndRestrictedStockUnitsMember_f474a28c-fcc7-407b-b4e7-27d227cf7282" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockMember_0675ea9c-0708-4a32-8568-652f42f69296" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8e8a6123-125e-4628-ba03-b9c76d90d81f" xlink:to="loc_us-gaap_EmployeeStockMember_0675ea9c-0708-4a32-8568-652f42f69296" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_PostCombinationExpenseMember_4b0717f5-ee67-45a3-9be5-96a135270731" xlink:href="enph-20240630.xsd#enph_PostCombinationExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8e8a6123-125e-4628-ba03-b9c76d90d81f" xlink:to="loc_enph_PostCombinationExpenseMember_4b0717f5-ee67-45a3-9be5-96a135270731" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_80494b99-bbfb-49da-a701-d689787fcfd3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b5304709-e277-428d-8e36-f3dc8fd479a6" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_80494b99-bbfb-49da-a701-d689787fcfd3" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/STOCKBASEDCOMPENSATIONSummaryofStockOptionsOutstandingDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#STOCKBASEDCOMPENSATIONSummaryofStockOptionsOutstandingDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/STOCKBASEDCOMPENSATIONSummaryofStockOptionsOutstandingDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_a41a3f66-d2bf-4576-b30c-1aab7bc1d63d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_2a2c3e54-f964-4859-8f54-1d4e87256259" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_a41a3f66-d2bf-4576-b30c-1aab7bc1d63d" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_2a2c3e54-f964-4859-8f54-1d4e87256259" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_6a389fed-c151-421d-b96b-fa0a7a39ac1e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_2a2c3e54-f964-4859-8f54-1d4e87256259" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_6a389fed-c151-421d-b96b-fa0a7a39ac1e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_6a389fed-c151-421d-b96b-fa0a7a39ac1e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_6a389fed-c151-421d-b96b-fa0a7a39ac1e" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_6a389fed-c151-421d-b96b-fa0a7a39ac1e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_18cac155-5a4d-4962-b483-eb68d1e284d9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_6a389fed-c151-421d-b96b-fa0a7a39ac1e" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_18cac155-5a4d-4962-b483-eb68d1e284d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_RangeOneMember_5345dfda-cc55-445e-a887-d6d33677b5bb" xlink:href="enph-20240630.xsd#enph_RangeOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_18cac155-5a4d-4962-b483-eb68d1e284d9" xlink:to="loc_enph_RangeOneMember_5345dfda-cc55-445e-a887-d6d33677b5bb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_RangeTwoMember_d20a4f91-9279-4034-b85d-e7a07bc630ba" xlink:href="enph-20240630.xsd#enph_RangeTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_18cac155-5a4d-4962-b483-eb68d1e284d9" xlink:to="loc_enph_RangeTwoMember_d20a4f91-9279-4034-b85d-e7a07bc630ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_RangeThreeMember_78bbe2d6-d10c-49be-894c-ad4625120520" xlink:href="enph-20240630.xsd#enph_RangeThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_18cac155-5a4d-4962-b483-eb68d1e284d9" xlink:to="loc_enph_RangeThreeMember_78bbe2d6-d10c-49be-894c-ad4625120520" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_RangeFourMember_904bb7c8-36fa-4f6e-bfa5-d0e987a83a48" xlink:href="enph-20240630.xsd#enph_RangeFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_18cac155-5a4d-4962-b483-eb68d1e284d9" xlink:to="loc_enph_RangeFourMember_904bb7c8-36fa-4f6e-bfa5-d0e987a83a48" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_075219ee-733f-4bd2-91a2-ad690c7a4028" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_a41a3f66-d2bf-4576-b30c-1aab7bc1d63d" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_075219ee-733f-4bd2-91a2-ad690c7a4028" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_a570af4e-f8eb-4feb-a993-b0799445db46" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_a41a3f66-d2bf-4576-b30c-1aab7bc1d63d" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_a570af4e-f8eb-4feb-a993-b0799445db46" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions_1fa26a82-4cbf-4fc5-b08e-0442f43375b2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_a41a3f66-d2bf-4576-b30c-1aab7bc1d63d" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions_1fa26a82-4cbf-4fc5-b08e-0442f43375b2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2_23f6a92f-09d3-47f1-9efd-38fa20573dff" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_a41a3f66-d2bf-4576-b30c-1aab7bc1d63d" xlink:to="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2_23f6a92f-09d3-47f1-9efd-38fa20573dff" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1_6d45eb16-9de9-4b53-9370-b58c65a5ae81" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_a41a3f66-d2bf-4576-b30c-1aab7bc1d63d" xlink:to="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1_6d45eb16-9de9-4b53-9370-b58c65a5ae81" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions_e100a73b-06c1-410b-a60d-d2c267461a7b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_a41a3f66-d2bf-4576-b30c-1aab7bc1d63d" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions_e100a73b-06c1-410b-a60d-d2c267461a7b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_9c8dc1d8-6546-4dcd-856e-44da82efde63" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_a41a3f66-d2bf-4576-b30c-1aab7bc1d63d" xlink:to="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_9c8dc1d8-6546-4dcd-856e-44da82efde63" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/STOCKBASEDCOMPENSATIONSummaryofRestrictedStockUnitActivityDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#STOCKBASEDCOMPENSATIONSummaryofRestrictedStockUnitActivityDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/STOCKBASEDCOMPENSATIONSummaryofRestrictedStockUnitActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b44ad505-cf8a-4944-a4af-94c81e5043e9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8e7a7b7b-0cdd-400f-a433-25f321b8f9b6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b44ad505-cf8a-4944-a4af-94c81e5043e9" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8e7a7b7b-0cdd-400f-a433-25f321b8f9b6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_b21bce16-2e68-4cc8-b9b1-c85005012d5c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8e7a7b7b-0cdd-400f-a433-25f321b8f9b6" xlink:to="loc_us-gaap_AwardTypeAxis_b21bce16-2e68-4cc8-b9b1-c85005012d5c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b21bce16-2e68-4cc8-b9b1-c85005012d5c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_b21bce16-2e68-4cc8-b9b1-c85005012d5c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b21bce16-2e68-4cc8-b9b1-c85005012d5c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7cc4a1d9-18da-4952-896a-19cbe98cf04c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_b21bce16-2e68-4cc8-b9b1-c85005012d5c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7cc4a1d9-18da-4952-896a-19cbe98cf04c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_9958764d-239c-4c50-898f-2bbd3ca0f93c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7cc4a1d9-18da-4952-896a-19cbe98cf04c" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_9958764d-239c-4c50-898f-2bbd3ca0f93c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_a30c8e96-b3ba-4092-937e-488a7f0eedec" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b44ad505-cf8a-4944-a4af-94c81e5043e9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_a30c8e96-b3ba-4092-937e-488a7f0eedec" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_273ffbe7-2336-45a2-af90-e0cc31bf5524" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_a30c8e96-b3ba-4092-937e-488a7f0eedec" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_273ffbe7-2336-45a2-af90-e0cc31bf5524" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_1e64f101-087b-4b37-b997-e793fb3466c6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_a30c8e96-b3ba-4092-937e-488a7f0eedec" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_1e64f101-087b-4b37-b997-e793fb3466c6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_9ee44907-825b-45c6-97ac-6a40a11e9159" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_a30c8e96-b3ba-4092-937e-488a7f0eedec" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_9ee44907-825b-45c6-97ac-6a40a11e9159" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_048a4a01-2922-41a3-ad93-8a6d77421a77" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_a30c8e96-b3ba-4092-937e-488a7f0eedec" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_048a4a01-2922-41a3-ad93-8a6d77421a77" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_d785c975-e16a-448e-93bf-c3d01c153ac7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestOutstandingNumber_3d09da82-05b2-47fb-893d-f9fd05ae8a02" xlink:href="enph-20240630.xsd#enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b44ad505-cf8a-4944-a4af-94c81e5043e9" xlink:to="loc_enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestOutstandingNumber_3d09da82-05b2-47fb-893d-f9fd05ae8a02" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_c77c823e-e327-400f-9087-b01db47b827e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b44ad505-cf8a-4944-a4af-94c81e5043e9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_c77c823e-e327-400f-9087-b01db47b827e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_6e0cb2cb-5525-481d-bc2a-03c5749efa46" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_c77c823e-e327-400f-9087-b01db47b827e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_6e0cb2cb-5525-481d-bc2a-03c5749efa46" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_fe33df81-356a-4127-9b9a-78aba670fa41" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_c77c823e-e327-400f-9087-b01db47b827e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_fe33df81-356a-4127-9b9a-78aba670fa41" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_567c7582-e6b3-4746-9789-5435d418c16a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_c77c823e-e327-400f-9087-b01db47b827e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_567c7582-e6b3-4746-9789-5435d418c16a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_6a942eef-d9ef-4373-8583-0363a2db9da9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_c77c823e-e327-400f-9087-b01db47b827e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_6a942eef-d9ef-4373-8583-0363a2db9da9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_c8e14e0d-e7bb-41c6-b767-1dd944f0bcc0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestOutstandingWeightedAverageExercisePrice_3521214c-ddbe-4b2c-9017-7a14b92b1c1d" xlink:href="enph-20240630.xsd#enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestOutstandingWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b44ad505-cf8a-4944-a4af-94c81e5043e9" xlink:to="loc_enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestOutstandingWeightedAverageExercisePrice_3521214c-ddbe-4b2c-9017-7a14b92b1c1d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_WeightedAverageRemainingContractualTerm_30bb84c6-d367-4122-b338-9d3975a1dd94" xlink:href="enph-20240630.xsd#enph_WeightedAverageRemainingContractualTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b44ad505-cf8a-4944-a4af-94c81e5043e9" xlink:to="loc_enph_WeightedAverageRemainingContractualTerm_30bb84c6-d367-4122-b338-9d3975a1dd94" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_87312a31-5924-4003-bd80-72ae9c7e8161" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_enph_WeightedAverageRemainingContractualTerm_30bb84c6-d367-4122-b338-9d3975a1dd94" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_87312a31-5924-4003-bd80-72ae9c7e8161" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardOtherThanOptionsExpectedToVestWeightedAverageRemainingContractualTerm_92bd9d18-fddb-4fcb-95bc-8998480e4804" xlink:href="enph-20240630.xsd#enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardOtherThanOptionsExpectedToVestWeightedAverageRemainingContractualTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_enph_WeightedAverageRemainingContractualTerm_30bb84c6-d367-4122-b338-9d3975a1dd94" xlink:to="loc_enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardOtherThanOptionsExpectedToVestWeightedAverageRemainingContractualTerm_92bd9d18-fddb-4fcb-95bc-8998480e4804" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract_19ac0d82-63bd-4dc3-a9d7-51f943150977" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b44ad505-cf8a-4944-a4af-94c81e5043e9" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract_19ac0d82-63bd-4dc3-a9d7-51f943150977" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested_f9fb8fdd-5475-484c-8563-a17dbd0ec85b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract_19ac0d82-63bd-4dc3-a9d7-51f943150977" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested_f9fb8fdd-5475-484c-8563-a17dbd0ec85b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_a0f45b92-33a6-4aae-a7ed-c1d657de8c5e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract_19ac0d82-63bd-4dc3-a9d7-51f943150977" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_a0f45b92-33a6-4aae-a7ed-c1d657de8c5e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestIntrinsicValueValue_a8499f4a-50e1-4c25-a5d6-7ee26d545e81" xlink:href="enph-20240630.xsd#enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestIntrinsicValueValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract_19ac0d82-63bd-4dc3-a9d7-51f943150977" xlink:to="loc_enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestIntrinsicValueValue_a8499f4a-50e1-4c25-a5d6-7ee26d545e81" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharePrice_aa6929d0-ff6a-43a7-a77a-84cd43465531" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b44ad505-cf8a-4944-a4af-94c81e5043e9" xlink:to="loc_us-gaap_SharePrice_aa6929d0-ff6a-43a7-a77a-84cd43465531" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/STOCKBASEDCOMPENSATIONSummaryofPerformanceStockUnitActivityDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#STOCKBASEDCOMPENSATIONSummaryofPerformanceStockUnitActivityDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/STOCKBASEDCOMPENSATIONSummaryofPerformanceStockUnitActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ef857e17-9dc4-45d2-844f-40d31c159a96" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_d658f537-d5eb-400c-b780-958e0cde3f1e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ef857e17-9dc4-45d2-844f-40d31c159a96" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_d658f537-d5eb-400c-b780-958e0cde3f1e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_c79e6fff-89a8-491a-9577-670383a12135" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_d658f537-d5eb-400c-b780-958e0cde3f1e" xlink:to="loc_us-gaap_AwardTypeAxis_c79e6fff-89a8-491a-9577-670383a12135" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c79e6fff-89a8-491a-9577-670383a12135_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_c79e6fff-89a8-491a-9577-670383a12135" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c79e6fff-89a8-491a-9577-670383a12135_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_736fd918-d815-44a5-a627-e850be00acc3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_c79e6fff-89a8-491a-9577-670383a12135" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_736fd918-d815-44a5-a627-e850be00acc3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_b694d884-5869-4e32-802f-418462176b19" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_736fd918-d815-44a5-a627-e850be00acc3" xlink:to="loc_us-gaap_PerformanceSharesMember_b694d884-5869-4e32-802f-418462176b19" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_b7943d40-0f15-41db-8b22-0be7abe40e4c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ef857e17-9dc4-45d2-844f-40d31c159a96" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_b7943d40-0f15-41db-8b22-0be7abe40e4c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_529883db-ba6d-4027-aa59-b293fc91f392" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_b7943d40-0f15-41db-8b22-0be7abe40e4c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_529883db-ba6d-4027-aa59-b293fc91f392" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_76662538-01e2-4641-9579-83648580362e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_b7943d40-0f15-41db-8b22-0be7abe40e4c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_76662538-01e2-4641-9579-83648580362e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_16cf6b1d-f096-4aeb-83b9-2f9d15973f9d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_b7943d40-0f15-41db-8b22-0be7abe40e4c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_16cf6b1d-f096-4aeb-83b9-2f9d15973f9d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_a8d56620-ab44-4a2a-94e9-0931fd734f03" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_b7943d40-0f15-41db-8b22-0be7abe40e4c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_a8d56620-ab44-4a2a-94e9-0931fd734f03" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_d97731c1-a231-446f-b9f8-488d2bf609ce" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestOutstandingNumber_0b7b5903-668f-42f3-aff0-206f052d9502" xlink:href="enph-20240630.xsd#enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ef857e17-9dc4-45d2-844f-40d31c159a96" xlink:to="loc_enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestOutstandingNumber_0b7b5903-668f-42f3-aff0-206f052d9502" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_aebdb450-87bd-4fac-ad82-4d33ebaa6da9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ef857e17-9dc4-45d2-844f-40d31c159a96" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_aebdb450-87bd-4fac-ad82-4d33ebaa6da9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_1d1eaf00-9e36-4ceb-849e-4a478da5b9d6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_aebdb450-87bd-4fac-ad82-4d33ebaa6da9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_1d1eaf00-9e36-4ceb-849e-4a478da5b9d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_071c4b8f-ef2c-4e7f-abea-02dcfa083524" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_aebdb450-87bd-4fac-ad82-4d33ebaa6da9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_071c4b8f-ef2c-4e7f-abea-02dcfa083524" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_ded87de8-cad9-4d2c-8274-cc6cd0ccec6d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_aebdb450-87bd-4fac-ad82-4d33ebaa6da9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_ded87de8-cad9-4d2c-8274-cc6cd0ccec6d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_72ea0054-4dfe-4286-afbb-38dd79a9fd04" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_aebdb450-87bd-4fac-ad82-4d33ebaa6da9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_72ea0054-4dfe-4286-afbb-38dd79a9fd04" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_c4a8e267-3d6b-4705-a9df-49ad78ff25a9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestOutstandingWeightedAverageExercisePrice_c9e68a95-8441-429d-abe6-7dfccdf7d88d" xlink:href="enph-20240630.xsd#enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestOutstandingWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ef857e17-9dc4-45d2-844f-40d31c159a96" xlink:to="loc_enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestOutstandingWeightedAverageExercisePrice_c9e68a95-8441-429d-abe6-7dfccdf7d88d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_WeightedAverageRemainingContractualTerm_4e2a0f44-5db1-4960-864a-4d2a1bc0e353" xlink:href="enph-20240630.xsd#enph_WeightedAverageRemainingContractualTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ef857e17-9dc4-45d2-844f-40d31c159a96" xlink:to="loc_enph_WeightedAverageRemainingContractualTerm_4e2a0f44-5db1-4960-864a-4d2a1bc0e353" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_c56c3842-d7b7-4a80-beda-37b29dfc8894" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_enph_WeightedAverageRemainingContractualTerm_4e2a0f44-5db1-4960-864a-4d2a1bc0e353" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_c56c3842-d7b7-4a80-beda-37b29dfc8894" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardOtherThanOptionsExpectedToVestWeightedAverageRemainingContractualTerm_b6a01d0c-1b4b-4cc6-815f-62ccc0871cae" xlink:href="enph-20240630.xsd#enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardOtherThanOptionsExpectedToVestWeightedAverageRemainingContractualTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_enph_WeightedAverageRemainingContractualTerm_4e2a0f44-5db1-4960-864a-4d2a1bc0e353" xlink:to="loc_enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardOtherThanOptionsExpectedToVestWeightedAverageRemainingContractualTerm_b6a01d0c-1b4b-4cc6-815f-62ccc0871cae" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract_71656a68-581a-42eb-bdfc-c2bc9f2cc862" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ef857e17-9dc4-45d2-844f-40d31c159a96" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract_71656a68-581a-42eb-bdfc-c2bc9f2cc862" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested_b5bea0cd-a887-4024-8125-f089effe2bc8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract_71656a68-581a-42eb-bdfc-c2bc9f2cc862" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested_b5bea0cd-a887-4024-8125-f089effe2bc8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_d90dbb2a-b90d-49ba-bd91-cb52681ea46c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract_71656a68-581a-42eb-bdfc-c2bc9f2cc862" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_d90dbb2a-b90d-49ba-bd91-cb52681ea46c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestIntrinsicValueValue_15d82103-3787-4d8c-94c0-18eb5f52a2e1" xlink:href="enph-20240630.xsd#enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestIntrinsicValueValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ef857e17-9dc4-45d2-844f-40d31c159a96" xlink:to="loc_enph_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestIntrinsicValueValue_15d82103-3787-4d8c-94c0-18eb5f52a2e1" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharePrice_866bfd9d-6308-4c7c-aa26-bff17c36c376" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ef857e17-9dc4-45d2-844f-40d31c159a96" xlink:to="loc_us-gaap_SharePrice_866bfd9d-6308-4c7c-aa26-bff17c36c376" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/NETINCOMELOSSPERSHAREScheduleofComputationofBasicandDilutedNetIncomePerShareDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#NETINCOMELOSSPERSHAREScheduleofComputationofBasicandDilutedNetIncomePerShareDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/NETINCOMELOSSPERSHAREScheduleofComputationofBasicandDilutedNetIncomePerShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_6ebcaee0-4307-4850-ac97-c113947e16e1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_fcab6416-b679-4c7d-a0fa-25829e5564a0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_6ebcaee0-4307-4850-ac97-c113947e16e1" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_fcab6416-b679-4c7d-a0fa-25829e5564a0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_7b68365f-dd1e-400a-a90a-e0c53b08716f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_fcab6416-b679-4c7d-a0fa-25829e5564a0" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_7b68365f-dd1e-400a-a90a-e0c53b08716f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_7b68365f-dd1e-400a-a90a-e0c53b08716f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_7b68365f-dd1e-400a-a90a-e0c53b08716f" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_7b68365f-dd1e-400a-a90a-e0c53b08716f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_1bf4b854-577f-46ed-b669-4b06c3e75e9a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_7b68365f-dd1e-400a-a90a-e0c53b08716f" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_1bf4b854-577f-46ed-b669-4b06c3e75e9a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleNotesPayableMember_ce0943f2-b276-4168-ac19-4749a6e2b07d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConvertibleNotesPayableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_1bf4b854-577f-46ed-b669-4b06c3e75e9a" xlink:to="loc_us-gaap_ConvertibleNotesPayableMember_ce0943f2-b276-4168-ac19-4749a6e2b07d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_0595ce9f-7045-46f7-878d-47b8c44778a5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_fcab6416-b679-4c7d-a0fa-25829e5564a0" xlink:to="loc_us-gaap_DebtInstrumentAxis_0595ce9f-7045-46f7-878d-47b8c44778a5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_0595ce9f-7045-46f7-878d-47b8c44778a5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_0595ce9f-7045-46f7-878d-47b8c44778a5" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_0595ce9f-7045-46f7-878d-47b8c44778a5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_be5b8030-6540-4d7c-aa52-9a68bc4875c1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_0595ce9f-7045-46f7-878d-47b8c44778a5" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_be5b8030-6540-4d7c-aa52-9a68bc4875c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2023Member_a9be500b-bacc-4dc0-a39a-8f983b1e84d2" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2023Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_be5b8030-6540-4d7c-aa52-9a68bc4875c1" xlink:to="loc_enph_ConvertibleSeniorNotesDue2023Member_a9be500b-bacc-4dc0-a39a-8f983b1e84d2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2025Member_e9457451-63cb-4679-ae12-6dbf4771437e" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_be5b8030-6540-4d7c-aa52-9a68bc4875c1" xlink:to="loc_enph_ConvertibleSeniorNotesDue2025Member_e9457451-63cb-4679-ae12-6dbf4771437e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2026Member_5e2a36b3-35f6-4a8f-a071-712711b963ba" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_be5b8030-6540-4d7c-aa52-9a68bc4875c1" xlink:to="loc_enph_ConvertibleSeniorNotesDue2026Member_5e2a36b3-35f6-4a8f-a071-712711b963ba" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2028Member_f7fd6221-67ab-45e8-b014-9a14567632ce" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_be5b8030-6540-4d7c-aa52-9a68bc4875c1" xlink:to="loc_enph_ConvertibleSeniorNotesDue2028Member_f7fd6221-67ab-45e8-b014-9a14567632ce" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAbstract_f9f6adc3-4a7a-497f-9612-15ef4e354207" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLossAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_6ebcaee0-4307-4850-ac97-c113947e16e1" xlink:to="loc_us-gaap_NetIncomeLossAbstract_f9f6adc3-4a7a-497f-9612-15ef4e354207" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_1f867734-e2cc-4f93-9484-aa5d24368ea7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAbstract_f9f6adc3-4a7a-497f-9612-15ef4e354207" xlink:to="loc_us-gaap_NetIncomeLoss_1f867734-e2cc-4f93-9484-aa5d24368ea7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestOnConvertibleDebtNetOfTax_4f77fa69-135e-4a48-9b9c-5cf955440dbf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestOnConvertibleDebtNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAbstract_f9f6adc3-4a7a-497f-9612-15ef4e354207" xlink:to="loc_us-gaap_InterestOnConvertibleDebtNetOfTax_4f77fa69-135e-4a48-9b9c-5cf955440dbf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToParentDiluted_8a8dcd92-8d5d-4bd7-b916-4b6ad3877f31" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLossAttributableToParentDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAbstract_f9f6adc3-4a7a-497f-9612-15ef4e354207" xlink:to="loc_us-gaap_NetIncomeLossAttributableToParentDiluted_8a8dcd92-8d5d-4bd7-b916-4b6ad3877f31" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_6a1b3852-9441-4ae9-a98c-48722d002952" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_6ebcaee0-4307-4850-ac97-c113947e16e1" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_6a1b3852-9441-4ae9-a98c-48722d002952" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_affa9ce4-4d41-4e99-9b25-ddea3f4984dc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_6a1b3852-9441-4ae9-a98c-48722d002952" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_affa9ce4-4d41-4e99-9b25-ddea3f4984dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_886e8997-1580-4d32-9e75-a60707ac35c2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_6a1b3852-9441-4ae9-a98c-48722d002952" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_886e8997-1580-4d32-9e75-a60707ac35c2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToConversionOfDebtSecurities_77cda45b-8c33-499c-a7b3-69fa3b8d65d9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncrementalCommonSharesAttributableToConversionOfDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_6a1b3852-9441-4ae9-a98c-48722d002952" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToConversionOfDebtSecurities_77cda45b-8c33-499c-a7b3-69fa3b8d65d9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToCallOptionsAndWarrants_fd1c61dd-5fb0-4d90-9312-18a7d19f545c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncrementalCommonSharesAttributableToCallOptionsAndWarrants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_6a1b3852-9441-4ae9-a98c-48722d002952" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToCallOptionsAndWarrants_fd1c61dd-5fb0-4d90-9312-18a7d19f545c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_fdd982a4-be75-4879-a09f-ac1934ace167" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_6a1b3852-9441-4ae9-a98c-48722d002952" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_fdd982a4-be75-4879-a09f-ac1934ace167" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_EarningsPerShareBasicAndDilutedEPSAbstract_a032fe80-4d2c-44a0-a688-2335b8807097" xlink:href="enph-20240630.xsd#enph_EarningsPerShareBasicAndDilutedEPSAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_6ebcaee0-4307-4850-ac97-c113947e16e1" xlink:to="loc_enph_EarningsPerShareBasicAndDilutedEPSAbstract_a032fe80-4d2c-44a0-a688-2335b8807097" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_4057f192-e304-4a2b-a5c4-c75ae1a4d4c2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_enph_EarningsPerShareBasicAndDilutedEPSAbstract_a032fe80-4d2c-44a0-a688-2335b8807097" xlink:to="loc_us-gaap_EarningsPerShareBasic_4057f192-e304-4a2b-a5c4-c75ae1a4d4c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_13819ec5-1475-444f-8651-41bb4eefd769" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_enph_EarningsPerShareBasicAndDilutedEPSAbstract_a032fe80-4d2c-44a0-a688-2335b8807097" xlink:to="loc_us-gaap_EarningsPerShareDiluted_13819ec5-1475-444f-8651-41bb4eefd769" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://enphase.com/role/NETINCOMELOSSPERSHAREScheduleofPotentiallyDilutiveSecuritiesExcludedfromtheComputationofDilutedNetIncomePerShareDetails" xlink:type="simple" xlink:href="enph-20240630.xsd#NETINCOMELOSSPERSHAREScheduleofPotentiallyDilutiveSecuritiesExcludedfromtheComputationofDilutedNetIncomePerShareDetails"/>
  <link:definitionLink xlink:role="http://enphase.com/role/NETINCOMELOSSPERSHAREScheduleofPotentiallyDilutiveSecuritiesExcludedfromtheComputationofDilutedNetIncomePerShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_8b11555b-604d-4309-b654-aaf9dc6ea817" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_52af4566-8fe7-4eab-8c0e-dd3fc58b6126" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_8b11555b-604d-4309-b654-aaf9dc6ea817" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_52af4566-8fe7-4eab-8c0e-dd3fc58b6126" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_8e7d09ac-3856-4ff1-b6c7-02c093ca9736" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_52af4566-8fe7-4eab-8c0e-dd3fc58b6126" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_8e7d09ac-3856-4ff1-b6c7-02c093ca9736" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_8e7d09ac-3856-4ff1-b6c7-02c093ca9736_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_8e7d09ac-3856-4ff1-b6c7-02c093ca9736" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_8e7d09ac-3856-4ff1-b6c7-02c093ca9736_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_9e3a868d-5b4f-4410-9eaf-7522278ec534" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_8e7d09ac-3856-4ff1-b6c7-02c093ca9736" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_9e3a868d-5b4f-4410-9eaf-7522278ec534" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockCompensationPlanMember_cba4092e-0aaa-4026-a5cd-63930b0d806f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockCompensationPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_9e3a868d-5b4f-4410-9eaf-7522278ec534" xlink:to="loc_us-gaap_StockCompensationPlanMember_cba4092e-0aaa-4026-a5cd-63930b0d806f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_9d95e21c-fe64-45c4-aa9b-0e3ecf28c067" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_9e3a868d-5b4f-4410-9eaf-7522278ec534" xlink:to="loc_us-gaap_WarrantMember_9d95e21c-fe64-45c4-aa9b-0e3ecf28c067" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtSecuritiesMember_0fc21b0c-cbc1-4eaf-9d14-f436088947a5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConvertibleDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_9e3a868d-5b4f-4410-9eaf-7522278ec534" xlink:to="loc_us-gaap_ConvertibleDebtSecuritiesMember_0fc21b0c-cbc1-4eaf-9d14-f436088947a5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_e84ceaaa-48d7-4924-99e4-413a0e3dfe5e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_52af4566-8fe7-4eab-8c0e-dd3fc58b6126" xlink:to="loc_us-gaap_DebtInstrumentAxis_e84ceaaa-48d7-4924-99e4-413a0e3dfe5e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_e84ceaaa-48d7-4924-99e4-413a0e3dfe5e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_e84ceaaa-48d7-4924-99e4-413a0e3dfe5e" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_e84ceaaa-48d7-4924-99e4-413a0e3dfe5e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_98d1187d-dee0-4082-93fa-3c04b0edcc51" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_e84ceaaa-48d7-4924-99e4-413a0e3dfe5e" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_98d1187d-dee0-4082-93fa-3c04b0edcc51" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2025Member_ab2e7cba-1376-4f09-af4f-bde564bfdf82" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_98d1187d-dee0-4082-93fa-3c04b0edcc51" xlink:to="loc_enph_ConvertibleSeniorNotesDue2025Member_ab2e7cba-1376-4f09-af4f-bde564bfdf82" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2028Member_40bc8af6-6e29-415a-8ec5-ae4151612851" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_98d1187d-dee0-4082-93fa-3c04b0edcc51" xlink:to="loc_enph_ConvertibleSeniorNotesDue2028Member_40bc8af6-6e29-415a-8ec5-ae4151612851" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_ConvertibleSeniorNotesDue2026Member_12433eca-bb65-4c12-bfd8-63f700e9d106" xlink:href="enph-20240630.xsd#enph_ConvertibleSeniorNotesDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_98d1187d-dee0-4082-93fa-3c04b0edcc51" xlink:to="loc_enph_ConvertibleSeniorNotesDue2026Member_12433eca-bb65-4c12-bfd8-63f700e9d106" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_2ec65878-e7d0-47ed-9395-2763e246ec10" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_8b11555b-604d-4309-b654-aaf9dc6ea817" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_2ec65878-e7d0-47ed-9395-2763e246ec10" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/ecd/AwardTypeOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#AwardTypeOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/ecd/AwardTypeOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_EmployeeStockOptionsAndRestrictedStockUnitsMember_385e7dd1-c12b-47e9-8976-b1792dd01a95" xlink:href="enph-20240630.xsd#enph_EmployeeStockOptionsAndRestrictedStockUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_enph_EmployeeStockOptionsAndRestrictedStockUnitsMember_385e7dd1-c12b-47e9-8976-b1792dd01a95" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_us-gaap_EmployeeStockMember" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_enph_PostCombinationExpenseMember_88427f1d-cebf-4eb4-8743-ab02486a0e75" xlink:href="enph-20240630.xsd#enph_PostCombinationExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_enph_PostCombinationExpenseMember_88427f1d-cebf-4eb4-8743-ab02486a0e75" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_us-gaap_PerformanceSharesMember" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="simple" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-roles-2024.xsd#eedm"/>
  <link:definitionLink xlink:role="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent" xlink:type="arc" order="1"/>
  </link:definitionLink>
</link:linkbase>
