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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019e03cb-1123-78da-aa06-ecbac4b60267,g:2dc6fb82-6110-4335-b4cc-e9be24adf5f2-->
<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://www.facebook.com/role/CoverPage" xlink:type="simple" xlink:href="meta-20260630.xsd#CoverPage"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/CoverPage" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitiesTable_019e03cb-1205-7664-b4cb-c6e40284a0cb" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_EntitiesTable_019e03cb-1205-7664-b4cb-c6e40284a0cb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019e03cb-1205-7450-99b0-2c52e324e5a2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntitiesTable_019e03cb-1205-7664-b4cb-c6e40284a0cb" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019e03cb-1205-7450-99b0-2c52e324e5a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e03cb-1205-7450-99b0-2c52e324e5a2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e03cb-1205-7450-99b0-2c52e324e5a2" xlink:to="loc_us-gaap_ClassOfStockDomain_019e03cb-1205-7450-99b0-2c52e324e5a2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e03cb-1205-7207-8d02-0982c9412e07" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e03cb-1205-7450-99b0-2c52e324e5a2" xlink:to="loc_us-gaap_ClassOfStockDomain_019e03cb-1205-7207-8d02-0982c9412e07" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019e03cb-1205-7fb2-9a72-8ff583772ddf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019e03cb-1205-7207-8d02-0982c9412e07" xlink:to="loc_us-gaap_CommonClassAMember_019e03cb-1205-7fb2-9a72-8ff583772ddf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019e03cb-1205-7213-a4df-dedb9600c27e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019e03cb-1205-7207-8d02-0982c9412e07" xlink:to="loc_us-gaap_CommonClassBMember_019e03cb-1205-7213-a4df-dedb9600c27e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_019e03cb-1205-7342-8342-0429ddf6f33e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_DocumentType_019e03cb-1205-7342-8342-0429ddf6f33e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentQuarterlyReport_019e03cb-1205-7814-a258-c6ac8d7e94b1" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentQuarterlyReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_DocumentQuarterlyReport_019e03cb-1205-7814-a258-c6ac8d7e94b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_019e03cb-1205-72c4-9372-7866985aed78" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_DocumentPeriodEndDate_019e03cb-1205-72c4-9372-7866985aed78" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_019e03cb-1205-7eca-81fb-a996414f9eba" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_DocumentTransitionReport_019e03cb-1205-7eca-81fb-a996414f9eba" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_019e03cb-1205-7c21-845b-200a191388d8" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_EntityFileNumber_019e03cb-1205-7c21-845b-200a191388d8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_019e03cb-1205-78b5-807d-4bbea532bf68" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_EntityRegistrantName_019e03cb-1205-78b5-807d-4bbea532bf68" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_019e03cb-1205-74c4-9209-eecfdcd78d9c" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_EntityIncorporationStateCountryCode_019e03cb-1205-74c4-9209-eecfdcd78d9c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_019e03cb-1205-7ec0-ad38-683f5c8cc603" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_EntityTaxIdentificationNumber_019e03cb-1205-7ec0-ad38-683f5c8cc603" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_019e03cb-1205-72f4-b75f-13017de2e20b" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_EntityAddressAddressLine1_019e03cb-1205-72f4-b75f-13017de2e20b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_019e03cb-1205-7bb0-9887-85c72abdeab1" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_EntityAddressCityOrTown_019e03cb-1205-7bb0-9887-85c72abdeab1" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_019e03cb-1205-7e79-8b56-fa7fd5255ce9" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_EntityAddressStateOrProvince_019e03cb-1205-7e79-8b56-fa7fd5255ce9" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_019e03cb-1205-7a7b-8d1c-106958a2c306" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_EntityAddressPostalZipCode_019e03cb-1205-7a7b-8d1c-106958a2c306" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_019e03cb-1205-7d82-a12f-28103a1bfbec" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_CityAreaCode_019e03cb-1205-7d82-a12f-28103a1bfbec" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_019e03cb-1205-7a9f-8bc2-bad6df5b98c8" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_LocalPhoneNumber_019e03cb-1205-7a9f-8bc2-bad6df5b98c8" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_019e03cb-1205-7331-9682-3708bf73edf2" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_Security12bTitle_019e03cb-1205-7331-9682-3708bf73edf2" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_019e03cb-1205-7ead-96b5-8cb531b3addf" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_TradingSymbol_019e03cb-1205-7ead-96b5-8cb531b3addf" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_019e03cb-1205-736a-bf4e-daf37a80df36" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_SecurityExchangeName_019e03cb-1205-736a-bf4e-daf37a80df36" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_019e03cb-1205-72cb-a580-da8375c0d094" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_EntityCurrentReportingStatus_019e03cb-1205-72cb-a580-da8375c0d094" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_019e03cb-1205-7d1e-89bf-a93a02c3c7a4" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_EntityInteractiveDataCurrent_019e03cb-1205-7d1e-89bf-a93a02c3c7a4" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_019e03cb-1205-7a1b-83df-65419ea5d209" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_EntityFilerCategory_019e03cb-1205-7a1b-83df-65419ea5d209" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_019e03cb-1205-72dc-8678-9998963607bd" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_EntitySmallBusiness_019e03cb-1205-72dc-8678-9998963607bd" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_019e03cb-1205-752e-a4d9-d0686652dc35" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_EntityEmergingGrowthCompany_019e03cb-1205-752e-a4d9-d0686652dc35" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_019e03cb-1205-736b-9cb7-ab4097f9f76f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_EntityShellCompany_019e03cb-1205-736b-9cb7-ab4097f9f76f" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_019e03cb-1205-782c-9293-f6c134b4193f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_019e03cb-1205-782c-9293-f6c134b4193f" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_019e03cb-1205-775e-855e-6e0366021574" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_AmendmentFlag_019e03cb-1205-775e-855e-6e0366021574" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_019e03cb-1205-77f9-9155-9cf11fe7d898" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_DocumentFiscalYearFocus_019e03cb-1205-77f9-9155-9cf11fe7d898" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_019e03cb-1205-7ff7-8c5b-dd8dd4c95b40" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_DocumentFiscalPeriodFocus_019e03cb-1205-7ff7-8c5b-dd8dd4c95b40" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_019e03cb-1205-7b2c-b0ce-ed8de4a618d2" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_EntityCentralIndexKey_019e03cb-1205-7b2c-b0ce-ed8de4a618d2" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_019e03cb-1205-7676-b860-950497b5a1d7" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e03cb-1205-79ff-9829-4f88b2eba1c5" xlink:to="loc_dei_CurrentFiscalYearEndDate_019e03cb-1205-7676-b860-950497b5a1d7" xlink:type="arc" order="28"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETSParenthetical" xlink:type="simple" xlink:href="meta-20260630.xsd#CONDENSEDCONSOLIDATEDBALANCESHEETSParenthetical"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETSParenthetical" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019e03cb-1206-71cc-8375-7696e033fd3c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019e03cb-1206-79f2-849c-ba9d7998aadd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019e03cb-1206-71cc-8375-7696e033fd3c" xlink:to="loc_us-gaap_StatementTable_019e03cb-1206-79f2-849c-ba9d7998aadd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019e03cb-1206-704d-897c-52e945be3fda" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019e03cb-1206-79f2-849c-ba9d7998aadd" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019e03cb-1206-704d-897c-52e945be3fda" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e03cb-1206-704d-897c-52e945be3fda_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e03cb-1206-704d-897c-52e945be3fda" xlink:to="loc_us-gaap_ClassOfStockDomain_019e03cb-1206-704d-897c-52e945be3fda_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e03cb-1206-731c-80b7-33bce8a7d53d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e03cb-1206-704d-897c-52e945be3fda" xlink:to="loc_us-gaap_ClassOfStockDomain_019e03cb-1206-731c-80b7-33bce8a7d53d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019e03cb-1206-7701-aade-c30bf9286537" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019e03cb-1206-731c-80b7-33bce8a7d53d" xlink:to="loc_us-gaap_CommonClassAMember_019e03cb-1206-7701-aade-c30bf9286537" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019e03cb-1206-7466-9dde-6346dec98ffc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019e03cb-1206-731c-80b7-33bce8a7d53d" xlink:to="loc_us-gaap_CommonClassBMember_019e03cb-1206-7466-9dde-6346dec98ffc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityAbstract_019e03cb-1206-7570-abf1-6b828339da79" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e03cb-1206-71cc-8375-7696e033fd3c" xlink:to="loc_us-gaap_StockholdersEquityAbstract_019e03cb-1206-7570-abf1-6b828339da79" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_019e03cb-1206-7283-afba-8de7771b6e37" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_019e03cb-1206-7570-abf1-6b828339da79" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_019e03cb-1206-7283-afba-8de7771b6e37" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_019e03cb-1206-7304-9a36-8c46adf0152b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_019e03cb-1206-7570-abf1-6b828339da79" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_019e03cb-1206-7304-9a36-8c46adf0152b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_019e03cb-1206-70da-a58c-9e4f6179cd85" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_019e03cb-1206-7570-abf1-6b828339da79" xlink:to="loc_us-gaap_CommonStockSharesIssued_019e03cb-1206-70da-a58c-9e4f6179cd85" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019e03cb-1206-70e7-b390-505ca5871b4e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_019e03cb-1206-7570-abf1-6b828339da79" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019e03cb-1206-70e7-b390-505ca5871b4e" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY" xlink:type="simple" xlink:href="meta-20260630.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019e03cb-1206-736f-96b5-bb28c59e6932" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019e03cb-1206-707a-9c15-c11bed386dda" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019e03cb-1206-736f-96b5-bb28c59e6932" xlink:to="loc_us-gaap_StatementTable_019e03cb-1206-707a-9c15-c11bed386dda" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019e03cb-1206-709b-b977-379a49717679" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019e03cb-1206-707a-9c15-c11bed386dda" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019e03cb-1206-709b-b977-379a49717679" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019e03cb-1206-709b-b977-379a49717679_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019e03cb-1206-709b-b977-379a49717679" xlink:to="loc_us-gaap_EquityComponentDomain_019e03cb-1206-709b-b977-379a49717679_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019e03cb-1206-712f-9264-0b1e4bfcb9f2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019e03cb-1206-709b-b977-379a49717679" xlink:to="loc_us-gaap_EquityComponentDomain_019e03cb-1206-712f-9264-0b1e4bfcb9f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockIncludingAdditionalPaidInCapitalMember_019e03cb-1206-7098-911b-8c0fae933004" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockIncludingAdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e03cb-1206-712f-9264-0b1e4bfcb9f2" xlink:to="loc_us-gaap_CommonStockIncludingAdditionalPaidInCapitalMember_019e03cb-1206-7098-911b-8c0fae933004" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019e03cb-1206-7eaf-8cda-ea57edc0925b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e03cb-1206-712f-9264-0b1e4bfcb9f2" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019e03cb-1206-7eaf-8cda-ea57edc0925b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019e03cb-1206-7925-8dc5-e42e95757fd3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e03cb-1206-712f-9264-0b1e4bfcb9f2" xlink:to="loc_us-gaap_RetainedEarningsMember_019e03cb-1206-7925-8dc5-e42e95757fd3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e03cb-1206-7480-a56a-59521e7020cc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e03cb-1206-736f-96b5-bb28c59e6932" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e03cb-1206-7480-a56a-59521e7020cc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019e03cb-1206-7b22-9f28-0cf0a02aeaf0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e03cb-1206-7480-a56a-59521e7020cc" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019e03cb-1206-7b22-9f28-0cf0a02aeaf0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e03cb-1206-7a81-a1c9-be49344df91e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e03cb-1206-7480-a56a-59521e7020cc" xlink:to="loc_us-gaap_StockholdersEquity_019e03cb-1206-7a81-a1c9-be49344df91e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019e03cb-1206-76da-9913-2ca49b00e353" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e03cb-1206-7480-a56a-59521e7020cc" xlink:to="loc_us-gaap_NetIncomeLoss_019e03cb-1206-76da-9913-2ca49b00e353" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019e03cb-1206-751d-adfc-dcd4ecaa5dec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e03cb-1206-7480-a56a-59521e7020cc" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019e03cb-1206-751d-adfc-dcd4ecaa5dec" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_019e03cb-1206-7b5a-b156-52a7473b9349" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e03cb-1206-7480-a56a-59521e7020cc" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_019e03cb-1206-7b5a-b156-52a7473b9349" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_019e03cb-1206-765d-9b56-6ce990946ce3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e03cb-1206-7480-a56a-59521e7020cc" xlink:to="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_019e03cb-1206-765d-9b56-6ce990946ce3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_019e03cb-1206-75c4-b128-9a2e0726c5c6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e03cb-1206-7480-a56a-59521e7020cc" xlink:to="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_019e03cb-1206-75c4-b128-9a2e0726c5c6" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019e03cb-1206-763f-8209-7a256a4bff97" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e03cb-1206-7480-a56a-59521e7020cc" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019e03cb-1206-763f-8209-7a256a4bff97" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_019e03cb-1206-7a0f-84ef-28f5a5942ec6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e03cb-1206-7480-a56a-59521e7020cc" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_019e03cb-1206-7a0f-84ef-28f5a5942ec6" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_019e03cb-1206-7fcc-a19a-beb14f2042af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e03cb-1206-7480-a56a-59521e7020cc" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_019e03cb-1206-7fcc-a19a-beb14f2042af" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStock_019e03cb-1206-7e46-bc01-d5629548e9c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e03cb-1206-7480-a56a-59521e7020cc" xlink:to="loc_us-gaap_DividendsCommonStock_019e03cb-1206-7e46-bc01-d5629548e9c4" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityOther_019e03cb-1206-73cd-b637-13fe7ee9de2e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e03cb-1206-7480-a56a-59521e7020cc" xlink:to="loc_us-gaap_StockholdersEquityOther_019e03cb-1206-73cd-b637-13fe7ee9de2e" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019e03cb-1206-7d2f-8c41-d221c4f69545" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e03cb-1206-7cbd-a349-643b77f85319" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/RevenueDisaggregationofRevenueDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#RevenueDisaggregationofRevenueDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/RevenueDisaggregationofRevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019e03cb-1206-7d2c-99b3-c477d151d6ba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019e03cb-1206-70d7-a176-4a96e4b3cfeb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019e03cb-1206-7d2c-99b3-c477d151d6ba" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019e03cb-1206-70d7-a176-4a96e4b3cfeb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019e03cb-1206-796f-9b0c-e2993e2a282d" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019e03cb-1206-70d7-a176-4a96e4b3cfeb" xlink:to="loc_srt_ProductOrServiceAxis_019e03cb-1206-796f-9b0c-e2993e2a282d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019e03cb-1206-796f-9b0c-e2993e2a282d_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019e03cb-1206-796f-9b0c-e2993e2a282d" xlink:to="loc_srt_ProductsAndServicesDomain_019e03cb-1206-796f-9b0c-e2993e2a282d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019e03cb-1206-73aa-833d-949e5e5fda77" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019e03cb-1206-796f-9b0c-e2993e2a282d" xlink:to="loc_srt_ProductsAndServicesDomain_019e03cb-1206-73aa-833d-949e5e5fda77" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdvertisingMember_019e03cb-1206-7ae7-b9b1-ff1c6521261c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdvertisingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e03cb-1206-73aa-833d-949e5e5fda77" xlink:to="loc_us-gaap_AdvertisingMember_019e03cb-1206-7ae7-b9b1-ff1c6521261c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceOtherMember_019e03cb-1206-700d-8c48-ca66b3c7d442" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServiceOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e03cb-1206-73aa-833d-949e5e5fda77" xlink:to="loc_us-gaap_ServiceOtherMember_019e03cb-1206-700d-8c48-ca66b3c7d442" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019e03cb-1206-7bde-8ca7-4913c79d512f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019e03cb-1206-70d7-a176-4a96e4b3cfeb" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019e03cb-1206-7bde-8ca7-4913c79d512f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019e03cb-1206-7bde-8ca7-4913c79d512f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019e03cb-1206-7bde-8ca7-4913c79d512f" xlink:to="loc_us-gaap_SegmentDomain_019e03cb-1206-7bde-8ca7-4913c79d512f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019e03cb-1206-7def-8345-8ed06db4f405" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019e03cb-1206-7bde-8ca7-4913c79d512f" xlink:to="loc_us-gaap_SegmentDomain_019e03cb-1206-7def-8345-8ed06db4f405" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_FamilyOfAppsMember_019e03cb-1206-7ef3-8a2a-b80cf159517d" xlink:href="meta-20260630.xsd#meta_FamilyOfAppsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019e03cb-1206-7def-8345-8ed06db4f405" xlink:to="loc_meta_FamilyOfAppsMember_019e03cb-1206-7ef3-8a2a-b80cf159517d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_RealityLabsMember_019e03cb-1206-75f3-9930-81c8b59a310f" xlink:href="meta-20260630.xsd#meta_RealityLabsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019e03cb-1206-7def-8345-8ed06db4f405" xlink:to="loc_meta_RealityLabsMember_019e03cb-1206-75f3-9930-81c8b59a310f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019e03cb-1206-7f5d-a887-7e62570d436f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019e03cb-1206-70d7-a176-4a96e4b3cfeb" xlink:to="loc_srt_StatementGeographicalAxis_019e03cb-1206-7f5d-a887-7e62570d436f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019e03cb-1206-7f5d-a887-7e62570d436f_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019e03cb-1206-7f5d-a887-7e62570d436f" xlink:to="loc_srt_SegmentGeographicalDomain_019e03cb-1206-7f5d-a887-7e62570d436f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019e03cb-1206-786a-b359-1f21bd762ada" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019e03cb-1206-7f5d-a887-7e62570d436f" xlink:to="loc_srt_SegmentGeographicalDomain_019e03cb-1206-786a-b359-1f21bd762ada" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_USCanadaMember_019e03cb-1206-71bb-8b85-c6d70f904bc2" xlink:href="meta-20260630.xsd#meta_USCanadaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019e03cb-1206-786a-b359-1f21bd762ada" xlink:to="loc_meta_USCanadaMember_019e03cb-1206-71bb-8b85-c6d70f904bc2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EuropeMember_019e03cb-1206-724b-b2c3-d5701929ac15" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EuropeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019e03cb-1206-786a-b359-1f21bd762ada" xlink:to="loc_srt_EuropeMember_019e03cb-1206-724b-b2c3-d5701929ac15" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_019e03cb-1206-7840-bfae-610d28bd4d3c" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019e03cb-1206-786a-b359-1f21bd762ada" xlink:to="loc_srt_AsiaPacificMember_019e03cb-1206-7840-bfae-610d28bd4d3c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_RestOfWorldMember_019e03cb-1206-7a3c-92d4-c4d688f7425e" xlink:href="meta-20260630.xsd#meta_RestOfWorldMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019e03cb-1206-786a-b359-1f21bd762ada" xlink:to="loc_meta_RestOfWorldMember_019e03cb-1206-7a3c-92d4-c4d688f7425e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e03cb-1206-797e-985b-b6e839258a3d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019e03cb-1206-7d2c-99b3-c477d151d6ba" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e03cb-1206-797e-985b-b6e839258a3d" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/EarningsperShareBasicandDilutedEPSDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#EarningsperShareBasicandDilutedEPSDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/EarningsperShareBasicandDilutedEPSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasicLineItems_019e03cb-12d8-7378-aa7c-9fb9da0b36f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasicLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_019e03cb-12d8-7178-a101-c79f3b8f33c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_019e03cb-12d8-7378-aa7c-9fb9da0b36f8" xlink:to="loc_us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_019e03cb-12d8-7178-a101-c79f3b8f33c4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019e03cb-12d8-737d-9537-dce1d9d763aa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_019e03cb-12d8-7178-a101-c79f3b8f33c4" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019e03cb-12d8-737d-9537-dce1d9d763aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e03cb-12d8-737d-9537-dce1d9d763aa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e03cb-12d8-737d-9537-dce1d9d763aa" xlink:to="loc_us-gaap_ClassOfStockDomain_019e03cb-12d8-737d-9537-dce1d9d763aa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e03cb-12d8-7bde-ad9e-ec57b7e10bff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e03cb-12d8-737d-9537-dce1d9d763aa" xlink:to="loc_us-gaap_ClassOfStockDomain_019e03cb-12d8-7bde-ad9e-ec57b7e10bff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019e03cb-12d8-709a-ac6f-029f1482041a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019e03cb-12d8-7bde-ad9e-ec57b7e10bff" xlink:to="loc_us-gaap_CommonClassAMember_019e03cb-12d8-709a-ac6f-029f1482041a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019e03cb-12d8-7336-aee6-fcaf598b0d72" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019e03cb-12d8-7bde-ad9e-ec57b7e10bff" xlink:to="loc_us-gaap_CommonClassBMember_019e03cb-12d8-7336-aee6-fcaf598b0d72" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasicAbstract_019e03cb-12d8-7905-b334-869731a20243" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasicAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_019e03cb-12d8-7378-aa7c-9fb9da0b36f8" xlink:to="loc_us-gaap_EarningsPerShareBasicAbstract_019e03cb-12d8-7905-b334-869731a20243" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicAbstract_019e03cb-12d8-7ba3-b894-92941bc2dfad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_019e03cb-12d8-7905-b334-869731a20243" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicAbstract_019e03cb-12d8-7ba3-b894-92941bc2dfad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividends_019e03cb-12d8-764f-a63c-8a879e8c001f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfDividends"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicAbstract_019e03cb-12d8-7ba3-b894-92941bc2dfad" xlink:to="loc_us-gaap_PaymentsOfDividends_019e03cb-12d8-764f-a63c-8a879e8c001f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UndistributedEarnings_019e03cb-12d8-774a-9161-d93c93fc6eed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UndistributedEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicAbstract_019e03cb-12d8-7ba3-b894-92941bc2dfad" xlink:to="loc_us-gaap_UndistributedEarnings_019e03cb-12d8-774a-9161-d93c93fc6eed" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019e03cb-12d8-7ec9-88cf-081f42b84498" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicAbstract_019e03cb-12d8-7ba3-b894-92941bc2dfad" xlink:to="loc_us-gaap_NetIncomeLoss_019e03cb-12d8-7ec9-88cf-081f42b84498" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_019e03cb-12d8-7add-a4dd-9fa900a5dc31" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_019e03cb-12d8-7905-b334-869731a20243" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_019e03cb-12d8-7add-a4dd-9fa900a5dc31" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019e03cb-12d8-772f-ab87-02d8b7c1b37f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_019e03cb-12d8-7add-a4dd-9fa900a5dc31" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019e03cb-12d8-772f-ab87-02d8b7c1b37f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_019e03cb-12d8-7aa5-84b1-cfddad6075e0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_019e03cb-12d8-7905-b334-869731a20243" xlink:to="loc_us-gaap_EarningsPerShareBasic_019e03cb-12d8-7aa5-84b1-cfddad6075e0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDilutedAbstract_019e03cb-12d8-790e-9d45-a14defda9914" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDilutedAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_019e03cb-12d8-7378-aa7c-9fb9da0b36f8" xlink:to="loc_us-gaap_EarningsPerShareDilutedAbstract_019e03cb-12d8-790e-9d45-a14defda9914" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract_019e03cb-12d8-7c69-8057-6c9a897e91ac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedAbstract_019e03cb-12d8-790e-9d45-a14defda9914" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract_019e03cb-12d8-7c69-8057-6c9a897e91ac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToParentDiluted_019e03cb-12d8-7f73-8446-3605aed9a9e2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAttributableToParentDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract_019e03cb-12d8-7c69-8057-6c9a897e91ac" xlink:to="loc_us-gaap_NetIncomeLossAttributableToParentDiluted_019e03cb-12d8-7f73-8446-3605aed9a9e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019e03cb-12d8-76b6-9691-bfc634dfec7a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedAbstract_019e03cb-12d8-790e-9d45-a14defda9914" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019e03cb-12d8-76b6-9691-bfc634dfec7a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019e03cb-12d8-7853-a2b6-1632e5633f79" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_019e03cb-12d8-77d2-b238-4464254bcfaa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019e03cb-12d8-76b6-9691-bfc634dfec7a" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_019e03cb-12d8-77d2-b238-4464254bcfaa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019e03cb-12d8-71a7-a7b1-eeec25b798f2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019e03cb-12d8-76b6-9691-bfc634dfec7a" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019e03cb-12d8-71a7-a7b1-eeec25b798f2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_019e03cb-12d8-732c-b2ea-d815cd65613e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedAbstract_019e03cb-12d8-790e-9d45-a14defda9914" xlink:to="loc_us-gaap_EarningsPerShareDiluted_019e03cb-12d8-732c-b2ea-d815cd65613e" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/FinancialInstrumentsScheduleofAssetsMeasuredatFairValueonaRecurringBasisDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#FinancialInstrumentsScheduleofAssetsMeasuredatFairValueonaRecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/FinancialInstrumentsScheduleofAssetsMeasuredatFairValueonaRecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e03cb-12d8-71f7-8b24-19f98c5e879c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e03cb-12d8-7b9d-bf89-233d1a84a64e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e03cb-12d8-71f7-8b24-19f98c5e879c" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e03cb-12d8-7b9d-bf89-233d1a84a64e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e03cb-12d8-73fc-b570-cd8d5dbdcd1a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e03cb-12d8-7b9d-bf89-233d1a84a64e" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e03cb-12d8-73fc-b570-cd8d5dbdcd1a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e03cb-12d8-73fc-b570-cd8d5dbdcd1a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e03cb-12d8-73fc-b570-cd8d5dbdcd1a" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e03cb-12d8-73fc-b570-cd8d5dbdcd1a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e03cb-12d8-7327-b14b-9ad87ab34811" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e03cb-12d8-73fc-b570-cd8d5dbdcd1a" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e03cb-12d8-7327-b14b-9ad87ab34811" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019e03cb-12d8-7f69-bc57-c757db7b8244" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e03cb-12d8-7327-b14b-9ad87ab34811" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019e03cb-12d8-7f69-bc57-c757db7b8244" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019e03cb-12d8-7121-bb4b-02c6e10903a4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e03cb-12d8-7327-b14b-9ad87ab34811" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019e03cb-12d8-7121-bb4b-02c6e10903a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_019e03cb-12d8-731e-be22-6bb78a1ce463" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e03cb-12d8-7327-b14b-9ad87ab34811" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_019e03cb-12d8-731e-be22-6bb78a1ce463" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAxis_019e03cb-12d8-7f6b-8b92-312c8e817838" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e03cb-12d8-7b9d-bf89-233d1a84a64e" xlink:to="loc_us-gaap_CashAndCashEquivalentsAxis_019e03cb-12d8-7f6b-8b92-312c8e817838" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-7f6b-8b92-312c8e817838_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_019e03cb-12d8-7f6b-8b92-312c8e817838" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-7f6b-8b92-312c8e817838_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-73df-b2e4-9f71ea4bdb7e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_019e03cb-12d8-7f6b-8b92-312c8e817838" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-73df-b2e4-9f71ea4bdb7e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_019e03cb-12d8-7ec2-ba02-395751c5b6be" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MoneyMarketFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-73df-b2e4-9f71ea4bdb7e" xlink:to="loc_us-gaap_MoneyMarketFundsMember_019e03cb-12d8-7ec2-ba02-395751c5b6be" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USGovernmentDebtSecuritiesMember_019e03cb-12d8-77ec-bfd6-c0a07ed2590d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USGovernmentDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-73df-b2e4-9f71ea4bdb7e" xlink:to="loc_us-gaap_USGovernmentDebtSecuritiesMember_019e03cb-12d8-77ec-bfd6-c0a07ed2590d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BankTimeDepositsMember_019e03cb-12d8-7a63-abd7-f337920c072a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BankTimeDepositsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-73df-b2e4-9f71ea4bdb7e" xlink:to="loc_us-gaap_BankTimeDepositsMember_019e03cb-12d8-7a63-abd7-f337920c072a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_019e03cb-12d8-779d-92fb-ecae4166f23f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-73df-b2e4-9f71ea4bdb7e" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_019e03cb-12d8-779d-92fb-ecae4166f23f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_019e03cb-12d8-7438-8c79-54d3f3c13732" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e03cb-12d8-7b9d-bf89-233d1a84a64e" xlink:to="loc_us-gaap_FinancialInstrumentAxis_019e03cb-12d8-7438-8c79-54d3f3c13732" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e03cb-12d8-7438-8c79-54d3f3c13732_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019e03cb-12d8-7438-8c79-54d3f3c13732" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e03cb-12d8-7438-8c79-54d3f3c13732_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e03cb-12d8-7fd5-b1b1-a09f3136a70d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019e03cb-12d8-7438-8c79-54d3f3c13732" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e03cb-12d8-7fd5-b1b1-a09f3136a70d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USGovernmentDebtSecuritiesMember_019e03cb-12d8-7f45-9a6b-8d64337e2ec0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USGovernmentDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e03cb-12d8-7fd5-b1b1-a09f3136a70d" xlink:to="loc_us-gaap_USGovernmentDebtSecuritiesMember_019e03cb-12d8-7f45-9a6b-8d64337e2ec0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_019e03cb-12d8-79d3-b428-26fb7ab390d3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USGovernmentAgenciesDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e03cb-12d8-7fd5-b1b1-a09f3136a70d" xlink:to="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_019e03cb-12d8-79d3-b428-26fb7ab390d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_019e03cb-12d8-7423-90bc-752b49ad2677" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e03cb-12d8-7fd5-b1b1-a09f3136a70d" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_019e03cb-12d8-7423-90bc-752b49ad2677" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019e03cb-12d8-7692-948a-e4d0c43a5e4d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e03cb-12d8-71f7-8b24-19f98c5e879c" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019e03cb-12d8-7692-948a-e4d0c43a5e4d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019e03cb-12d8-7cfd-9b00-9dc88a73ef1e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e03cb-12d8-71f7-8b24-19f98c5e879c" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019e03cb-12d8-7cfd-9b00-9dc88a73ef1e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNi_019e03cb-12d8-71c8-8902-c191f210e9a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesFvNi"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e03cb-12d8-71f7-8b24-19f98c5e879c" xlink:to="loc_us-gaap_EquitySecuritiesFvNi_019e03cb-12d8-71c8-8902-c191f210e9a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecuritiesCurrent_019e03cb-12d8-7d8c-8ff7-d29782774d6d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MarketableSecuritiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e03cb-12d8-71f7-8b24-19f98c5e879c" xlink:to="loc_us-gaap_MarketableSecuritiesCurrent_019e03cb-12d8-7d8c-8ff7-d29782774d6d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_RestrictedCashEquivalentsFairValueDisclosure_019e03cb-12d8-7e38-8ebc-61e436152c7d" xlink:href="meta-20260630.xsd#meta_RestrictedCashEquivalentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e03cb-12d8-71f7-8b24-19f98c5e879c" xlink:to="loc_meta_RestrictedCashEquivalentsFairValueDisclosure_019e03cb-12d8-7e38-8ebc-61e436152c7d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsFairValueDisclosure_019e03cb-12d8-71c7-a1d6-a52d574c6329" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e03cb-12d8-71f7-8b24-19f98c5e879c" xlink:to="loc_us-gaap_OtherAssetsFairValueDisclosure_019e03cb-12d8-71c7-a1d6-a52d574c6329" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_019e03cb-12d8-7885-89a2-3de60f76675f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e03cb-12d8-71f7-8b24-19f98c5e879c" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_019e03cb-12d8-7885-89a2-3de60f76675f" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/FinancialInstrumentsNarrativeDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#FinancialInstrumentsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/FinancialInstrumentsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e03cb-12d8-7dbe-a08f-604f5187fb15" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e03cb-12d8-7aeb-8488-4cad79dabd0d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e03cb-12d8-7dbe-a08f-604f5187fb15" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e03cb-12d8-7aeb-8488-4cad79dabd0d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_019e03cb-12d8-779c-b1d0-122813aa3726" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e03cb-12d8-7aeb-8488-4cad79dabd0d" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_019e03cb-12d8-779c-b1d0-122813aa3726" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-779c-b1d0-122813aa3726_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_019e03cb-12d8-779c-b1d0-122813aa3726" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-779c-b1d0-122813aa3726_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-7b79-8e99-f7cc50b74348" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_019e03cb-12d8-779c-b1d0-122813aa3726" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-7b79-8e99-f7cc50b74348" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_019e03cb-12d8-7e4f-b851-bf5ab6cf1f21" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MoneyMarketFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-7b79-8e99-f7cc50b74348" xlink:to="loc_us-gaap_MoneyMarketFundsMember_019e03cb-12d8-7e4f-b851-bf5ab6cf1f21" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_RestrictedCashEquivalentsFairValueDisclosure_019e03cb-12d8-7c62-b52b-105e5cccf7a3" xlink:href="meta-20260630.xsd#meta_RestrictedCashEquivalentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e03cb-12d8-7dbe-a08f-604f5187fb15" xlink:to="loc_meta_RestrictedCashEquivalentsFairValueDisclosure_019e03cb-12d8-7c62-b52b-105e5cccf7a3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedGainLossBeforeTax_019e03cb-12d8-7f68-9d3e-bac7d09d3804" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedGainLossBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e03cb-12d8-7dbe-a08f-604f5187fb15" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedGainLossBeforeTax_019e03cb-12d8-7f68-9d3e-bac7d09d3804" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss_019e03cb-12d8-7ffc-b3e7-766205bec79f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e03cb-12d8-7dbe-a08f-604f5187fb15" xlink:to="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss_019e03cb-12d8-7ffc-b3e7-766205bec79f" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/FinancialInstrumentsAvailableforsaleMarketableSecuritiesDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#FinancialInstrumentsAvailableforsaleMarketableSecuritiesDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/FinancialInstrumentsAvailableforsaleMarketableSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecuritiesLineItems_019e03cb-12d8-7e58-befd-029e7275d332" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MarketableSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecuritiesTable_019e03cb-12d8-7246-9d48-d191a0d82013" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MarketableSecuritiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019e03cb-12d8-7e58-befd-029e7275d332" xlink:to="loc_us-gaap_MarketableSecuritiesTable_019e03cb-12d8-7246-9d48-d191a0d82013" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_019e03cb-12d8-700c-8a62-d7e6fdcdcc47" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MarketableSecuritiesTable_019e03cb-12d8-7246-9d48-d191a0d82013" xlink:to="loc_us-gaap_FinancialInstrumentAxis_019e03cb-12d8-700c-8a62-d7e6fdcdcc47" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e03cb-12d8-700c-8a62-d7e6fdcdcc47_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019e03cb-12d8-700c-8a62-d7e6fdcdcc47" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e03cb-12d8-700c-8a62-d7e6fdcdcc47_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e03cb-12d8-722e-9d48-f417e6db49e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019e03cb-12d8-700c-8a62-d7e6fdcdcc47" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e03cb-12d8-722e-9d48-f417e6db49e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USGovernmentDebtSecuritiesMember_019e03cb-12d8-77ce-bcea-65624d0f8110" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USGovernmentDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e03cb-12d8-722e-9d48-f417e6db49e8" xlink:to="loc_us-gaap_USGovernmentDebtSecuritiesMember_019e03cb-12d8-77ce-bcea-65624d0f8110" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_019e03cb-12d8-7827-8836-d524780ed36c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USGovernmentAgenciesDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e03cb-12d8-722e-9d48-f417e6db49e8" xlink:to="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_019e03cb-12d8-7827-8836-d524780ed36c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_019e03cb-12d8-7f0d-9cea-3c9bda8d18ad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019e03cb-12d8-722e-9d48-f417e6db49e8" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_019e03cb-12d8-7f0d-9cea-3c9bda8d18ad" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_019e03cb-12d8-716b-b170-8e6fa059af17" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019e03cb-12d8-7e58-befd-029e7275d332" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_019e03cb-12d8-716b-b170-8e6fa059af17" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_019e03cb-12d8-7074-80b9-432f56c687d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019e03cb-12d8-7e58-befd-029e7275d332" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_019e03cb-12d8-7074-80b9-432f56c687d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_019e03cb-12d8-78af-9972-44fe1db9c77f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019e03cb-12d8-7e58-befd-029e7275d332" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_019e03cb-12d8-78af-9972-44fe1db9c77f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_019e03cb-12d8-7e83-b97b-378f7a74bf1c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019e03cb-12d8-7e58-befd-029e7275d332" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_019e03cb-12d8-7e83-b97b-378f7a74bf1c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_019e03cb-12d8-71f1-8d2b-dc2d01d68c2e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019e03cb-12d8-7e58-befd-029e7275d332" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_019e03cb-12d8-71f1-8d2b-dc2d01d68c2e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_019e03cb-12d8-7023-bd5b-e66b98571163" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019e03cb-12d8-7e58-befd-029e7275d332" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_019e03cb-12d8-7023-bd5b-e66b98571163" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/NonMarketableEquityInvestmentsNarrativeDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#NonMarketableEquityInvestmentsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/NonMarketableEquityInvestmentsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019e03cb-12d8-76b6-b451-dcbb1ea8dd38" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueTable_019e03cb-12d8-7ff5-be2d-9ccb6865c5f1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019e03cb-12d8-76b6-b451-dcbb1ea8dd38" xlink:to="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueTable_019e03cb-12d8-7ff5-be2d-9ccb6865c5f1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019e03cb-12d8-7a36-b28f-857b6e6afadf" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueTable_019e03cb-12d8-7ff5-be2d-9ccb6865c5f1" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019e03cb-12d8-7a36-b28f-857b6e6afadf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019e03cb-12d8-7a36-b28f-857b6e6afadf_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019e03cb-12d8-7a36-b28f-857b6e6afadf" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019e03cb-12d8-7a36-b28f-857b6e6afadf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019e03cb-12d8-7fea-98bf-21533c849a98" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019e03cb-12d8-7a36-b28f-857b6e6afadf" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019e03cb-12d8-7fea-98bf-21533c849a98" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_DataCenterCampusInLouisianaMember_019e03cb-12d8-76ac-afac-c50129f866b5" xlink:href="meta-20260630.xsd#meta_DataCenterCampusInLouisianaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_019e03cb-12d8-7fea-98bf-21533c849a98" xlink:to="loc_meta_DataCenterCampusInLouisianaMember_019e03cb-12d8-76ac-afac-c50129f866b5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_019e03cb-12d8-7e9d-8c7f-84ae436ef52c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019e03cb-12d8-76b6-b451-dcbb1ea8dd38" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_019e03cb-12d8-7e9d-8c7f-84ae436ef52c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_VentureEstimatedDevelopmentCosts_019e03cb-12d8-753c-8963-0a6e79f3573d" xlink:href="meta-20260630.xsd#meta_VentureEstimatedDevelopmentCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019e03cb-12d8-76b6-b451-dcbb1ea8dd38" xlink:to="loc_meta_VentureEstimatedDevelopmentCosts_019e03cb-12d8-753c-8963-0a6e79f3573d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount_019e03cb-12d8-7060-b23a-f59564d1f7f5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019e03cb-12d8-76b6-b451-dcbb1ea8dd38" xlink:to="loc_us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount_019e03cb-12d8-7060-b23a-f59564d1f7f5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecordedUnconditionalPurchaseObligationTerm_019e03cb-12d8-7962-be2b-adfdc9e01cef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrecordedUnconditionalPurchaseObligationTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019e03cb-12d8-76b6-b451-dcbb1ea8dd38" xlink:to="loc_us-gaap_UnrecordedUnconditionalPurchaseObligationTerm_019e03cb-12d8-7962-be2b-adfdc9e01cef" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_UnrecordedUnconditionalPurchaseObligationOptionalRenewalTermMaximumTotalLeasePeriod_019e03cb-12d8-7934-89d3-50274d113184" xlink:href="meta-20260630.xsd#meta_UnrecordedUnconditionalPurchaseObligationOptionalRenewalTermMaximumTotalLeasePeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019e03cb-12d8-76b6-b451-dcbb1ea8dd38" xlink:to="loc_meta_UnrecordedUnconditionalPurchaseObligationOptionalRenewalTermMaximumTotalLeasePeriod_019e03cb-12d8-7934-89d3-50274d113184" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_UnrecordedUnconditionalPurchaseObligationResidualValueGuaranteeMaximum_019e03cb-12d8-7170-9f0f-81db9d42f87e" xlink:href="meta-20260630.xsd#meta_UnrecordedUnconditionalPurchaseObligationResidualValueGuaranteeMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019e03cb-12d8-76b6-b451-dcbb1ea8dd38" xlink:to="loc_meta_UnrecordedUnconditionalPurchaseObligationResidualValueGuaranteeMaximum_019e03cb-12d8-7170-9f0f-81db9d42f87e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_019e03cb-12d8-7ada-a6a8-362c76d2b2e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019e03cb-12d8-76b6-b451-dcbb1ea8dd38" xlink:to="loc_us-gaap_EquityMethodInvestments_019e03cb-12d8-7ada-a6a8-362c76d2b2e8" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount_019e03cb-12d8-7d0f-aaec-a865bd906846" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueLineItems_019e03cb-12d8-76b6-b451-dcbb1ea8dd38" xlink:to="loc_us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount_019e03cb-12d8-7d0f-aaec-a865bd906846" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/PropertyandEquipmentSummaryDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#PropertyandEquipmentSummaryDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/PropertyandEquipmentSummaryDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e03cb-12d8-745c-a805-83bd0a8c765b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019e03cb-12d8-78e1-a625-28b559a386d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e03cb-12d8-745c-a805-83bd0a8c765b" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019e03cb-12d8-78e1-a625-28b559a386d2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019e03cb-12d8-7be9-a899-21b83874586f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019e03cb-12d8-78e1-a625-28b559a386d2" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019e03cb-12d8-7be9-a899-21b83874586f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e03cb-12d8-7be9-a899-21b83874586f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019e03cb-12d8-7be9-a899-21b83874586f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e03cb-12d8-7be9-a899-21b83874586f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e03cb-12d8-782a-9e19-8dd523de623b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019e03cb-12d8-7be9-a899-21b83874586f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e03cb-12d8-782a-9e19-8dd523de623b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandMember_019e03cb-12d8-7a41-894d-57511eedc100" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e03cb-12d8-782a-9e19-8dd523de623b" xlink:to="loc_us-gaap_LandMember_019e03cb-12d8-7a41-894d-57511eedc100" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_ServersAndNetworkAssetsMember_019e03cb-12d8-750a-bc94-b55812de26b5" xlink:href="meta-20260630.xsd#meta_ServersAndNetworkAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e03cb-12d8-782a-9e19-8dd523de623b" xlink:to="loc_meta_ServersAndNetworkAssetsMember_019e03cb-12d8-750a-bc94-b55812de26b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingMember_019e03cb-12d8-7a77-94fc-ae05bb0de4a2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BuildingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e03cb-12d8-782a-9e19-8dd523de623b" xlink:to="loc_us-gaap_BuildingMember_019e03cb-12d8-7a77-94fc-ae05bb0de4a2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_019e03cb-12d8-75d5-abd6-7e1fba076373" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e03cb-12d8-782a-9e19-8dd523de623b" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_019e03cb-12d8-75d5-abd6-7e1fba076373" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_EquipmentAndOtherMember_019e03cb-12d8-7c76-a597-bfe945312e0a" xlink:href="meta-20260630.xsd#meta_EquipmentAndOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e03cb-12d8-782a-9e19-8dd523de623b" xlink:to="loc_meta_EquipmentAndOtherMember_019e03cb-12d8-7c76-a597-bfe945312e0a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressMember_019e03cb-12d8-76cf-9f8b-4f1b06a8ca75" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConstructionInProgressMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e03cb-12d8-782a-9e19-8dd523de623b" xlink:to="loc_us-gaap_ConstructionInProgressMember_019e03cb-12d8-76cf-9f8b-4f1b06a8ca75" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_019e03cb-12d8-7c4b-b160-a7a05bc91e25" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e03cb-12d8-745c-a805-83bd0a8c765b" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_019e03cb-12d8-7c4b-b160-a7a05bc91e25" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization_019e03cb-12d8-7c5a-92d0-599a37de4b8e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e03cb-12d8-745c-a805-83bd0a8c765b" xlink:to="loc_us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization_019e03cb-12d8-7c5a-92d0-599a37de4b8e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization_019e03cb-12d8-73b3-91a6-94412d378697" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e03cb-12d8-745c-a805-83bd0a8c765b" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization_019e03cb-12d8-73b3-91a6-94412d378697" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization_019e03cb-12d8-78f7-8396-0a375fd868ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e03cb-12d8-745c-a805-83bd0a8c765b" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization_019e03cb-12d8-78f7-8396-0a375fd868ea" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_019e03cb-12d8-7b5f-ae73-0db74f340706" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e03cb-12d8-745c-a805-83bd0a8c765b" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_019e03cb-12d8-7b5f-ae73-0db74f340706" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/PropertyandEquipmentNarrativeDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#PropertyandEquipmentNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/PropertyandEquipmentNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e03cb-12d8-744c-8716-8fbc25a987e0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019e03cb-12d8-7a98-bd1f-47478bdb487b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e03cb-12d8-744c-8716-8fbc25a987e0" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019e03cb-12d8-7a98-bd1f-47478bdb487b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019e03cb-12d8-7f4d-8c69-7cc1fe0f1f19" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019e03cb-12d8-7a98-bd1f-47478bdb487b" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019e03cb-12d8-7f4d-8c69-7cc1fe0f1f19" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e03cb-12d8-7f4d-8c69-7cc1fe0f1f19_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019e03cb-12d8-7f4d-8c69-7cc1fe0f1f19" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e03cb-12d8-7f4d-8c69-7cc1fe0f1f19_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e03cb-12d8-7b54-8218-bb08a592ca76" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019e03cb-12d8-7f4d-8c69-7cc1fe0f1f19" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e03cb-12d8-7b54-8218-bb08a592ca76" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_ServersAndNetworkAssetsMember_019e03cb-12d8-7b79-be15-741e1a2cce28" xlink:href="meta-20260630.xsd#meta_ServersAndNetworkAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e03cb-12d8-7b54-8218-bb08a592ca76" xlink:to="loc_meta_ServersAndNetworkAssetsMember_019e03cb-12d8-7b79-be15-741e1a2cce28" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_019f7039-e4f1-7be1-a78a-420181a81fee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019e03cb-12d8-7a98-bd1f-47478bdb487b" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_019f7039-e4f1-7be1-a78a-420181a81fee" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_019f7039-e4f1-7be1-a78a-420181a81fee_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_019f7039-e4f1-7be1-a78a-420181a81fee" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_019f7039-e4f1-7be1-a78a-420181a81fee_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_019f7039-e4f1-765e-91ca-586cbd14614e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_019f7039-e4f1-7be1-a78a-420181a81fee" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_019f7039-e4f1-765e-91ca-586cbd14614e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember_019f7039-e4f1-7809-a945-8f61e3da4754" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_019f7039-e4f1-765e-91ca-586cbd14614e" xlink:to="loc_us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember_019f7039-e4f1-7809-a945-8f61e3da4754" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_019f7039-e4f1-7fe4-8ac8-9978166553e9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019e03cb-12d8-7a98-bd1f-47478bdb487b" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_019f7039-e4f1-7fe4-8ac8-9978166553e9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_019f7039-e4f1-7fe4-8ac8-9978166553e9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_019f7039-e4f1-7fe4-8ac8-9978166553e9" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_019f7039-e4f1-7fe4-8ac8-9978166553e9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_019f7039-e4f1-7429-a3f4-55430ea1b346" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_019f7039-e4f1-7fe4-8ac8-9978166553e9" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_019f7039-e4f1-7429-a3f4-55430ea1b346" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_ConstructionInProgressAndLandHeldForSaleMember_019f7039-e4f1-72cc-8a51-4bad9bfff492" xlink:href="meta-20260630.xsd#meta_ConstructionInProgressAndLandHeldForSaleMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_019f7039-e4f1-7429-a3f4-55430ea1b346" xlink:to="loc_meta_ConstructionInProgressAndLandHeldForSaleMember_019f7039-e4f1-72cc-8a51-4bad9bfff492" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation_019e03cb-12d8-7cf4-9c03-d40c825f6112" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Depreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e03cb-12d8-744c-8716-8fbc25a987e0" xlink:to="loc_us-gaap_Depreciation_019e03cb-12d8-7cf4-9c03-d40c825f6112" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent_019f7039-e4f1-7c69-94d3-82f8b87659aa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e03cb-12d8-744c-8716-8fbc25a987e0" xlink:to="loc_us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent_019f7039-e4f1-7c69-94d3-82f8b87659aa" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/AcquisitionsandGoodwillChangeinCarryingAmountofGoodwillDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#AcquisitionsandGoodwillChangeinCarryingAmountofGoodwillDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/AcquisitionsandGoodwillChangeinCarryingAmountofGoodwillDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019e03cb-12d8-7524-a3b9-47c0ce29e77f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e03cb-12d8-7ed3-90d8-1dfc62017b11" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e03cb-12d8-7524-a3b9-47c0ce29e77f" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e03cb-12d8-7ed3-90d8-1dfc62017b11" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019e03cb-12d8-721b-bc66-4fde3ffe821c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e03cb-12d8-7ed3-90d8-1dfc62017b11" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019e03cb-12d8-721b-bc66-4fde3ffe821c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019e03cb-12d8-721b-bc66-4fde3ffe821c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019e03cb-12d8-721b-bc66-4fde3ffe821c" xlink:to="loc_us-gaap_SegmentDomain_019e03cb-12d8-721b-bc66-4fde3ffe821c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019e03cb-12d8-7ea7-ba78-e94e3ce25e66" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019e03cb-12d8-721b-bc66-4fde3ffe821c" xlink:to="loc_us-gaap_SegmentDomain_019e03cb-12d8-7ea7-ba78-e94e3ce25e66" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_FamilyOfAppsMember_019e03cb-12d8-7bc6-9d9b-c3f100c6462f" xlink:href="meta-20260630.xsd#meta_FamilyOfAppsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019e03cb-12d8-7ea7-ba78-e94e3ce25e66" xlink:to="loc_meta_FamilyOfAppsMember_019e03cb-12d8-7bc6-9d9b-c3f100c6462f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_RealityLabsMember_019e03cb-12d8-70ef-9cfb-42d735f139ce" xlink:href="meta-20260630.xsd#meta_RealityLabsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019e03cb-12d8-7ea7-ba78-e94e3ce25e66" xlink:to="loc_meta_RealityLabsMember_019e03cb-12d8-70ef-9cfb-42d735f139ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_019e03cb-12d8-742d-b0c1-20c798524843" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e03cb-12d8-7524-a3b9-47c0ce29e77f" xlink:to="loc_us-gaap_GoodwillRollForward_019e03cb-12d8-742d-b0c1-20c798524843" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019e03cb-12d8-756f-be74-e5866c87a3e7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019e03cb-12d8-742d-b0c1-20c798524843" xlink:to="loc_us-gaap_Goodwill_019e03cb-12d8-756f-be74-e5866c87a3e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_019e03cb-12d8-7b6b-be32-457d9b275ee2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019e03cb-12d8-742d-b0c1-20c798524843" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_019e03cb-12d8-7b6b-be32-457d9b275ee2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_GoodwillReclassifiedToHeldForSale_019f5bbe-0836-7939-8a63-4e20fd1634a6" xlink:href="meta-20260630.xsd#meta_GoodwillReclassifiedToHeldForSale"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019e03cb-12d8-742d-b0c1-20c798524843" xlink:to="loc_meta_GoodwillReclassifiedToHeldForSale_019f5bbe-0836-7939-8a63-4e20fd1634a6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillOtherIncreaseDecrease_019e03cb-12d8-72dc-b85e-e454cef098c9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillOtherIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019e03cb-12d8-742d-b0c1-20c798524843" xlink:to="loc_us-gaap_GoodwillOtherIncreaseDecrease_019e03cb-12d8-72dc-b85e-e454cef098c9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019e03cb-12d8-7eed-96e3-fd8c467e3d6e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/LongtermDebtNarrativeDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#LongtermDebtNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/LongtermDebtNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019e03cb-12d8-7084-8a30-b30969e32fd2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019e03cb-12d8-7982-a1a0-d4f3b855f3e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019e03cb-12d8-7084-8a30-b30969e32fd2" xlink:to="loc_us-gaap_DebtInstrumentTable_019e03cb-12d8-7982-a1a0-d4f3b855f3e5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019e03cb-12d8-7592-a900-d784117df7a1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019e03cb-12d8-7982-a1a0-d4f3b855f3e5" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019e03cb-12d8-7592-a900-d784117df7a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019e03cb-12d8-7592-a900-d784117df7a1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019e03cb-12d8-7592-a900-d784117df7a1" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019e03cb-12d8-7592-a900-d784117df7a1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019e03cb-12d8-781d-b5a6-10f67fbab57e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019e03cb-12d8-7592-a900-d784117df7a1" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019e03cb-12d8-781d-b5a6-10f67fbab57e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_May2026DebtMember_019e2c98-1c9a-7c6b-b187-6601ca424efb" xlink:href="meta-20260630.xsd#meta_May2026DebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019e03cb-12d8-781d-b5a6-10f67fbab57e" xlink:to="loc_meta_May2026DebtMember_019e2c98-1c9a-7c6b-b187-6601ca424efb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_019e03cb-12d8-797b-a828-5e8228a657a1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019e03cb-12d8-781d-b5a6-10f67fbab57e" xlink:to="loc_us-gaap_SeniorNotesMember_019e03cb-12d8-797b-a828-5e8228a657a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_019e03cb-12d8-792e-b3ad-70f8106a1231" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019e03cb-12d8-7982-a1a0-d4f3b855f3e5" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_019e03cb-12d8-792e-b3ad-70f8106a1231" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019e03cb-12d8-792e-b3ad-70f8106a1231_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_019e03cb-12d8-792e-b3ad-70f8106a1231" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019e03cb-12d8-792e-b3ad-70f8106a1231_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019e03cb-12d8-71cb-a0fd-592e6fda25e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_019e03cb-12d8-792e-b3ad-70f8106a1231" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019e03cb-12d8-71cb-a0fd-592e6fda25e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019e03cb-12d8-7d25-8923-e441abf81a3c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019e03cb-12d8-71cb-a0fd-592e6fda25e8" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019e03cb-12d8-7d25-8923-e441abf81a3c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_019e03cb-12d8-73e6-a853-d9e396ec48f6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019e03cb-12d8-71cb-a0fd-592e6fda25e8" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_019e03cb-12d8-73e6-a853-d9e396ec48f6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e03cb-12d8-74a0-87e5-9e667aed70a5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019e03cb-12d8-7982-a1a0-d4f3b855f3e5" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e03cb-12d8-74a0-87e5-9e667aed70a5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e03cb-12d8-74a0-87e5-9e667aed70a5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e03cb-12d8-74a0-87e5-9e667aed70a5" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e03cb-12d8-74a0-87e5-9e667aed70a5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e03cb-12d8-7698-8e1a-675057a1230e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e03cb-12d8-74a0-87e5-9e667aed70a5" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e03cb-12d8-7698-8e1a-675057a1230e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019e03cb-12d8-77dd-85a5-c8c76676a1d3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e03cb-12d8-7698-8e1a-675057a1230e" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019e03cb-12d8-77dd-85a5-c8c76676a1d3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019e03cb-12d8-72fb-8b08-8b5d8c0dcabd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019e03cb-12d8-7084-8a30-b30969e32fd2" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019e03cb-12d8-72fb-8b08-8b5d8c0dcabd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_DebtInstrumentNumberOfSeries_019e8889-a5ce-7812-a880-f52891b6cffb" xlink:href="meta-20260630.xsd#meta_DebtInstrumentNumberOfSeries"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019e03cb-12d8-7084-8a30-b30969e32fd2" xlink:to="loc_meta_DebtInstrumentNumberOfSeries_019e8889-a5ce-7812-a880-f52891b6cffb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebt_019f5c1e-e1fb-7de7-8b41-2c2c930ca7d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019e03cb-12d8-7084-8a30-b30969e32fd2" xlink:to="loc_us-gaap_InterestExpenseDebt_019f5c1e-e1fb-7de7-8b41-2c2c930ca7d0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_019e03cb-12d8-7eea-bcd8-f66cd90fb532" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019e03cb-12d8-7084-8a30-b30969e32fd2" xlink:to="loc_us-gaap_LongTermDebtFairValue_019e03cb-12d8-7eea-bcd8-f66cd90fb532" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/LongtermDebtScheduleofCarryingValuesandEstimatedFairValuesofDebtInstrumentsDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#LongtermDebtScheduleofCarryingValuesandEstimatedFairValuesofDebtInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/LongtermDebtScheduleofCarryingValuesandEstimatedFairValuesofDebtInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019e03cb-12d8-7975-a956-ceaaf304c647" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019e03cb-12d8-74d4-88b6-6dcbd5ea5fb3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019e03cb-12d8-7975-a956-ceaaf304c647" xlink:to="loc_us-gaap_DebtInstrumentTable_019e03cb-12d8-74d4-88b6-6dcbd5ea5fb3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019e03cb-12d8-7b3b-88f5-cc58a4fc8e72" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019e03cb-12d8-74d4-88b6-6dcbd5ea5fb3" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019e03cb-12d8-7b3b-88f5-cc58a4fc8e72" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019e03cb-12d8-7b3b-88f5-cc58a4fc8e72_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019e03cb-12d8-7b3b-88f5-cc58a4fc8e72" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019e03cb-12d8-7b3b-88f5-cc58a4fc8e72_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019e03cb-12d8-7081-ba4b-47ce4db345dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019e03cb-12d8-7b3b-88f5-cc58a4fc8e72" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019e03cb-12d8-7081-ba4b-47ce4db345dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_August2022DebtMember_019e03cb-12d8-7bc2-b4fb-a7004186c688" xlink:href="meta-20260630.xsd#meta_August2022DebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019e03cb-12d8-7081-ba4b-47ce4db345dc" xlink:to="loc_meta_August2022DebtMember_019e03cb-12d8-7bc2-b4fb-a7004186c688" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_May2023DebtMember_019e03cb-12d8-76c1-9531-8076a26f98ea" xlink:href="meta-20260630.xsd#meta_May2023DebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019e03cb-12d8-7081-ba4b-47ce4db345dc" xlink:to="loc_meta_May2023DebtMember_019e03cb-12d8-76c1-9531-8076a26f98ea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_August2024DebtMember_019e03cb-12d8-72f7-8c1d-93d052a8a19a" xlink:href="meta-20260630.xsd#meta_August2024DebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019e03cb-12d8-7081-ba4b-47ce4db345dc" xlink:to="loc_meta_August2024DebtMember_019e03cb-12d8-72f7-8c1d-93d052a8a19a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_November2025DebtMember_019e2c9b-c7b4-7579-9366-486557520a8e" xlink:href="meta-20260630.xsd#meta_November2025DebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019e03cb-12d8-7081-ba4b-47ce4db345dc" xlink:to="loc_meta_November2025DebtMember_019e2c9b-c7b4-7579-9366-486557520a8e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_May2026DebtMember_019e2c9b-2c7c-7802-9c8f-ec023a0049bf" xlink:href="meta-20260630.xsd#meta_May2026DebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019e03cb-12d8-7081-ba4b-47ce4db345dc" xlink:to="loc_meta_May2026DebtMember_019e2c9b-2c7c-7802-9c8f-ec023a0049bf" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019e03cb-12d8-7ad2-957a-f3c99bf4d05c" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019e03cb-12d8-74d4-88b6-6dcbd5ea5fb3" xlink:to="loc_srt_RangeAxis_019e03cb-12d8-7ad2-957a-f3c99bf4d05c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019e03cb-12d8-7ad2-957a-f3c99bf4d05c_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019e03cb-12d8-7ad2-957a-f3c99bf4d05c" xlink:to="loc_srt_RangeMember_019e03cb-12d8-7ad2-957a-f3c99bf4d05c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019e03cb-12d8-7776-807e-8b87eb469bd4" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019e03cb-12d8-7ad2-957a-f3c99bf4d05c" xlink:to="loc_srt_RangeMember_019e03cb-12d8-7776-807e-8b87eb469bd4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019e03cb-12d8-7e80-b821-1ef5fa39c560" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019e03cb-12d8-7776-807e-8b87eb469bd4" xlink:to="loc_srt_MinimumMember_019e03cb-12d8-7e80-b821-1ef5fa39c560" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019e03cb-12d8-758a-bc09-c687b782c9b9" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019e03cb-12d8-7776-807e-8b87eb469bd4" xlink:to="loc_srt_MaximumMember_019e03cb-12d8-758a-bc09-c687b782c9b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019e03cb-12d8-7eb2-8242-7744fdfb2b5d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019e03cb-12d8-7975-a956-ceaaf304c647" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019e03cb-12d8-7eb2-8242-7744fdfb2b5d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_019e03cb-12d8-7a1b-890b-f584cca2de36" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019e03cb-12d8-7975-a956-ceaaf304c647" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_019e03cb-12d8-7a1b-890b-f584cca2de36" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_019e03cb-12d8-7099-b038-126a739fd295" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019e03cb-12d8-7975-a956-ceaaf304c647" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_019e03cb-12d8-7099-b038-126a739fd295" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_019e03cb-12d8-7a65-87e4-d9dad0b92165" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019e03cb-12d8-7975-a956-ceaaf304c647" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_019e03cb-12d8-7a65-87e4-d9dad0b92165" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019e03cb-12d8-72b7-b94a-135fb5ee2b4c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019e03cb-12d8-7975-a956-ceaaf304c647" xlink:to="loc_us-gaap_LongTermDebt_019e03cb-12d8-72b7-b94a-135fb5ee2b4c" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/CommitmentsandContingenciesDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#CommitmentsandContingenciesDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/CommitmentsandContingenciesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_019e03cb-12d8-7a80-bb10-f13e73b7cbda" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_us-gaap_LossContingenciesTable_019e03cb-12d8-7a80-bb10-f13e73b7cbda" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019e03cb-12d8-7c30-8713-45e1d5cd38e0" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019e03cb-12d8-7a80-bb10-f13e73b7cbda" xlink:to="loc_srt_RangeAxis_019e03cb-12d8-7c30-8713-45e1d5cd38e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019e03cb-12d8-7c30-8713-45e1d5cd38e0_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019e03cb-12d8-7c30-8713-45e1d5cd38e0" xlink:to="loc_srt_RangeMember_019e03cb-12d8-7c30-8713-45e1d5cd38e0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019e03cb-12d8-703d-ba5d-26090a49f060" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019e03cb-12d8-7c30-8713-45e1d5cd38e0" xlink:to="loc_srt_RangeMember_019e03cb-12d8-703d-ba5d-26090a49f060" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019e03cb-12d8-7baf-8b3d-827d78927de1" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019e03cb-12d8-703d-ba5d-26090a49f060" xlink:to="loc_srt_MinimumMember_019e03cb-12d8-7baf-8b3d-827d78927de1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019e03cb-12d8-7645-bad1-ed1ae150d34b" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019e03cb-12d8-703d-ba5d-26090a49f060" xlink:to="loc_srt_MaximumMember_019e03cb-12d8-7645-bad1-ed1ae150d34b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019fa84f-93a4-7b87-83c8-2e0a50911c60" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019e03cb-12d8-7a80-bb10-f13e73b7cbda" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019fa84f-93a4-7b87-83c8-2e0a50911c60" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019fa84f-93a4-7b87-83c8-2e0a50911c60_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019fa84f-93a4-7b87-83c8-2e0a50911c60" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019fa84f-93a4-7b87-83c8-2e0a50911c60_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019fa84f-93a4-7f35-b78b-a8382ac2243c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019fa84f-93a4-7b87-83c8-2e0a50911c60" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019fa84f-93a4-7f35-b78b-a8382ac2243c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019fa84f-a868-7e4e-826f-ed912316c48f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019fa84f-93a4-7f35-b78b-a8382ac2243c" xlink:to="loc_us-gaap_SubsequentEventMember_019fa84f-a868-7e4e-826f-ed912316c48f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsAxis_019e03cb-12d8-7378-99b9-c24c69847b96" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019e03cb-12d8-7a80-bb10-f13e73b7cbda" xlink:to="loc_us-gaap_OtherCommitmentsAxis_019e03cb-12d8-7378-99b9-c24c69847b96" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsDomain_019e03cb-12d8-7378-99b9-c24c69847b96_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_OtherCommitmentsAxis_019e03cb-12d8-7378-99b9-c24c69847b96" xlink:to="loc_us-gaap_OtherCommitmentsDomain_019e03cb-12d8-7378-99b9-c24c69847b96_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsDomain_019e03cb-12d8-7563-a24d-0ac9a8e7d663" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_OtherCommitmentsAxis_019e03cb-12d8-7378-99b9-c24c69847b96" xlink:to="loc_us-gaap_OtherCommitmentsDomain_019e03cb-12d8-7563-a24d-0ac9a8e7d663" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_ContingentObligationToPurchaseCloudCapacityMember_019e03cb-12d8-769b-a0fd-fa9cdb3c88ce" xlink:href="meta-20260630.xsd#meta_ContingentObligationToPurchaseCloudCapacityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsDomain_019e03cb-12d8-7563-a24d-0ac9a8e7d663" xlink:to="loc_meta_ContingentObligationToPurchaseCloudCapacityMember_019e03cb-12d8-769b-a0fd-fa9cdb3c88ce" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_019e03cb-12d8-79f7-b12b-11fb595c7667" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019e03cb-12d8-7a80-bb10-f13e73b7cbda" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_019e03cb-12d8-79f7-b12b-11fb595c7667" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-79f7-b12b-11fb595c7667_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_019e03cb-12d8-79f7-b12b-11fb595c7667" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-79f7-b12b-11fb595c7667_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-7d87-bf85-104653668f62" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis_019e03cb-12d8-79f7-b12b-11fb595c7667" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-7d87-bf85-104653668f62" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_019e03cb-12d8-79c5-ae86-84f001eb4d7a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MoneyMarketFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-7d87-bf85-104653668f62" xlink:to="loc_us-gaap_MoneyMarketFundsMember_019e03cb-12d8-79c5-ae86-84f001eb4d7a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationTypeAxis_019e03cb-12d8-786e-b085-9d30307a25dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019e03cb-12d8-7a80-bb10-f13e73b7cbda" xlink:to="loc_us-gaap_ReclassificationTypeAxis_019e03cb-12d8-786e-b085-9d30307a25dc" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationTypeDomain_019e03cb-12d8-786e-b085-9d30307a25dc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ReclassificationTypeAxis_019e03cb-12d8-786e-b085-9d30307a25dc" xlink:to="loc_us-gaap_ReclassificationTypeDomain_019e03cb-12d8-786e-b085-9d30307a25dc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationTypeDomain_019e03cb-12d8-7005-906f-373c7991bf4b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ReclassificationTypeAxis_019e03cb-12d8-786e-b085-9d30307a25dc" xlink:to="loc_us-gaap_ReclassificationTypeDomain_019e03cb-12d8-7005-906f-373c7991bf4b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOtherMember_019e03cb-12d8-7a22-9431-cf38053599fd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationTypeDomain_019e03cb-12d8-7005-906f-373c7991bf4b" xlink:to="loc_us-gaap_ReclassificationOtherMember_019e03cb-12d8-7a22-9431-cf38053599fd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAxis_019e03cb-12d8-7b4f-ab50-ec53a41f95be" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019e03cb-12d8-7a80-bb10-f13e73b7cbda" xlink:to="loc_us-gaap_CashAndCashEquivalentsAxis_019e03cb-12d8-7b4f-ab50-ec53a41f95be" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-7b4f-ab50-ec53a41f95be_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_019e03cb-12d8-7b4f-ab50-ec53a41f95be" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-7b4f-ab50-ec53a41f95be_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-787d-bb0e-ed84071e7cf6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_019e03cb-12d8-7b4f-ab50-ec53a41f95be" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019e03cb-12d8-787d-bb0e-ed84071e7cf6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_019e03cb-12d8-7c90-a31c-f65d5fdb1d7a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MoneyMarketFundsMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseAxis_019e03cb-12d8-7d9d-8f14-2ef60e27dc40" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_LitigationCaseAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019e03cb-12d8-7a80-bb10-f13e73b7cbda" xlink:to="loc_srt_LitigationCaseAxis_019e03cb-12d8-7d9d-8f14-2ef60e27dc40" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_019e03cb-12d8-7d9d-8f14-2ef60e27dc40_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_LitigationCaseAxis_019e03cb-12d8-7d9d-8f14-2ef60e27dc40" xlink:to="loc_srt_LitigationCaseTypeDomain_019e03cb-12d8-7d9d-8f14-2ef60e27dc40_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_019e03cb-12d8-7ce1-a5f8-71f73bb3e31a" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_LitigationCaseAxis_019e03cb-12d8-7d9d-8f14-2ef60e27dc40" xlink:to="loc_srt_LitigationCaseTypeDomain_019e03cb-12d8-7ce1-a5f8-71f73bb3e31a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_UnitedStatesFederalTradeCommissionInquiryMember_019e03cb-12d8-7973-b840-c4ab419146c8" xlink:href="meta-20260630.xsd#meta_UnitedStatesFederalTradeCommissionInquiryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_019e03cb-12d8-7ce1-a5f8-71f73bb3e31a" xlink:to="loc_meta_UnitedStatesFederalTradeCommissionInquiryMember_019e03cb-12d8-7973-b840-c4ab419146c8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_IDPCInquiryMember_019e03cb-12d8-7dc0-b027-ac51a18a59c2" xlink:href="meta-20260630.xsd#meta_IDPCInquiryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_019e03cb-12d8-7ce1-a5f8-71f73bb3e31a" xlink:to="loc_meta_IDPCInquiryMember_019e03cb-12d8-7dc0-b027-ac51a18a59c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_EuropeanCommissionStatementOfObjectionsMember_019e03cb-12d8-7cc5-a36e-0a35ead85643" xlink:href="meta-20260630.xsd#meta_EuropeanCommissionStatementOfObjectionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_019e03cb-12d8-7ce1-a5f8-71f73bb3e31a" xlink:to="loc_meta_EuropeanCommissionStatementOfObjectionsMember_019e03cb-12d8-7cc5-a36e-0a35ead85643" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_EuropeanCommissionSubscriptionForNoAdsMember_019e03cb-12d8-7e43-8805-3abf9efa559f" xlink:href="meta-20260630.xsd#meta_EuropeanCommissionSubscriptionForNoAdsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_019e03cb-12d8-7ce1-a5f8-71f73bb3e31a" xlink:to="loc_meta_EuropeanCommissionSubscriptionForNoAdsMember_019e03cb-12d8-7e43-8805-3abf9efa559f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_FrascoV.FloHealthInc.Member_019e03cb-12d8-7a39-9c6e-bb1af219774e" xlink:href="meta-20260630.xsd#meta_FrascoV.FloHealthInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_019e03cb-12d8-7ce1-a5f8-71f73bb3e31a" xlink:to="loc_meta_FrascoV.FloHealthInc.Member_019e03cb-12d8-7a39-9c6e-bb1af219774e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_AsociacionDeMediosDeInformacionAMIV.MetaIrelandMember_019e03cb-12d8-7db6-89d3-e1f530ddb55e" xlink:href="meta-20260630.xsd#meta_AsociacionDeMediosDeInformacionAMIV.MetaIrelandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_019e03cb-12d8-7ce1-a5f8-71f73bb3e31a" xlink:to="loc_meta_AsociacionDeMediosDeInformacionAMIV.MetaIrelandMember_019e03cb-12d8-7db6-89d3-e1f530ddb55e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_UnionDeTelevisionesComercialesAsociadasUTECAV.MetaIrelandMember_019e03cb-12d8-7da7-bd6e-2a8b16b5926b" xlink:href="meta-20260630.xsd#meta_UnionDeTelevisionesComercialesAsociadasUTECAV.MetaIrelandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_019e03cb-12d8-7ce1-a5f8-71f73bb3e31a" xlink:to="loc_meta_UnionDeTelevisionesComercialesAsociadasUTECAV.MetaIrelandMember_019e03cb-12d8-7da7-bd6e-2a8b16b5926b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_AmauryEtAl.V.MetaPlatformsIrelandLimitedMember_019e03cb-12d8-7841-b59a-fdb73f11074b" xlink:href="meta-20260630.xsd#meta_AmauryEtAl.V.MetaPlatformsIrelandLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_019e03cb-12d8-7ce1-a5f8-71f73bb3e31a" xlink:to="loc_meta_AmauryEtAl.V.MetaPlatformsIrelandLimitedMember_019e03cb-12d8-7841-b59a-fdb73f11074b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_YouthRelatedActionsBellwetherTrialsMember_019e03cb-12d8-7baf-b686-33dd77a47c80" xlink:href="meta-20260630.xsd#meta_YouthRelatedActionsBellwetherTrialsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_019e03cb-12d8-7ce1-a5f8-71f73bb3e31a" xlink:to="loc_meta_YouthRelatedActionsBellwetherTrialsMember_019e03cb-12d8-7baf-b686-33dd77a47c80" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_YouthRelatedActionsStateAttorneyGeneralCasesMember_019e03cb-12d8-79aa-85a9-1125794a30fb" xlink:href="meta-20260630.xsd#meta_YouthRelatedActionsStateAttorneyGeneralCasesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_019e03cb-12d8-7ce1-a5f8-71f73bb3e31a" xlink:to="loc_meta_YouthRelatedActionsStateAttorneyGeneralCasesMember_019e03cb-12d8-79aa-85a9-1125794a30fb" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019e03cb-12d8-773a-865f-ccf3c0687e23" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019e03cb-12d8-7a80-bb10-f13e73b7cbda" xlink:to="loc_dei_LegalEntityAxis_019e03cb-12d8-773a-865f-ccf3c0687e23" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e03cb-12d8-773a-865f-ccf3c0687e23_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019e03cb-12d8-773a-865f-ccf3c0687e23" xlink:to="loc_dei_EntityDomain_019e03cb-12d8-773a-865f-ccf3c0687e23_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019e03cb-12d8-7f79-85a8-944846de0ac6" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019e03cb-12d8-773a-865f-ccf3c0687e23" xlink:to="loc_dei_EntityDomain_019e03cb-12d8-7f79-85a8-944846de0ac6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_MetaPlatformsIrelandLimitedMember_019e03cb-12d8-7148-b9a1-3c1f63edfe4e" xlink:href="meta-20260630.xsd#meta_MetaPlatformsIrelandLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e03cb-12d8-7f79-85a8-944846de0ac6" xlink:to="loc_meta_MetaPlatformsIrelandLimitedMember_019e03cb-12d8-7148-b9a1-3c1f63edfe4e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_MetaYoutubeMember_019e03cb-12d8-7bb9-9fa5-780cee2b86e3" xlink:href="meta-20260630.xsd#meta_MetaYoutubeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e03cb-12d8-7f79-85a8-944846de0ac6" xlink:to="loc_meta_MetaYoutubeMember_019e03cb-12d8-7bb9-9fa5-780cee2b86e3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_YoutubeMember_019e03cb-12d8-7ab3-929f-13e537be12cb" xlink:href="meta-20260630.xsd#meta_YoutubeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019e03cb-12d8-7f79-85a8-944846de0ac6" xlink:to="loc_meta_YoutubeMember_019e03cb-12d8-7ab3-929f-13e537be12cb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount_019e03cb-12d8-7bfb-b8f6-e4db29f4a38f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount_019e03cb-12d8-7bfb-b8f6-e4db29f4a38f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1_019e03cb-12d9-7b95-be76-4dc72125bce3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_us-gaap_LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1_019e03cb-12d9-7b95-be76-4dc72125bce3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeFinanceLeaseLeaseNotYetCommencedTermOfContract1_019e03cb-12d9-715a-bc31-2af9ae22cc42" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeFinanceLeaseLeaseNotYetCommencedTermOfContract1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_us-gaap_LesseeFinanceLeaseLeaseNotYetCommencedTermOfContract1_019e03cb-12d9-715a-bc31-2af9ae22cc42" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligation_019e03cb-12d9-703a-a7f9-f22305ba58e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractualObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_us-gaap_ContractualObligation_019e03cb-12d9-703a-a7f9-f22305ba58e5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligationFutureMinimumPaymentsDueRemainderOfFiscalYear_019e03cb-12d9-73ca-94b6-b846e066101f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractualObligationFutureMinimumPaymentsDueRemainderOfFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_us-gaap_ContractualObligationFutureMinimumPaymentsDueRemainderOfFiscalYear_019e03cb-12d9-73ca-94b6-b846e066101f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligationDueInNextTwelveMonths_019e03cb-12d9-7ab5-a581-4a8c73537d0f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractualObligationDueInNextTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_us-gaap_ContractualObligationDueInNextTwelveMonths_019e03cb-12d9-7ab5-a581-4a8c73537d0f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitment_019e03cb-12d9-787b-a169-869eb6ea5c19" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_us-gaap_OtherCommitment_019e03cb-12d9-787b-a169-869eb6ea5c19" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_OtherCommitmentsPeriod_019e03cb-12d9-72a2-bf2b-ceb56723fafd" xlink:href="meta-20260630.xsd#meta_OtherCommitmentsPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_meta_OtherCommitmentsPeriod_019e03cb-12d9-72a2-bf2b-ceb56723fafd" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019e03cb-12d9-7c43-8dfa-a3c68503a482" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019e03cb-12d9-7c43-8dfa-a3c68503a482" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashEquivalents_019e03cb-12d9-71a3-a890-ab82ec0e51af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_us-gaap_RestrictedCashEquivalents_019e03cb-12d9-71a3-a890-ab82ec0e51af" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationSettlementAmountAwardedToOtherParty_019e03cb-12d9-7d29-b3c2-e817713c18ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LitigationSettlementAmountAwardedToOtherParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_us-gaap_LitigationSettlementAmountAwardedToOtherParty_019e03cb-12d9-7d29-b3c2-e817713c18ea" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualPayments_019e03cb-12d9-7dd5-8ff4-29cd261e070e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyAccrualPayments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_us-gaap_LossContingencyAccrualPayments_019e03cb-12d9-7dd5-8ff4-29cd261e070e" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyDamagesSoughtValue_019e03cb-12d9-7db2-a698-2a177f0a220e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyDamagesSoughtValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_us-gaap_LossContingencyDamagesSoughtValue_019e03cb-12d9-7db2-a698-2a177f0a220e" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_LitigationStatusUpdatePeriodFollowingDecisionInCase_019f703d-e7f8-7e7d-b20f-094b318e4942" xlink:href="meta-20260630.xsd#meta_LitigationStatusUpdatePeriodFollowingDecisionInCase"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_meta_LitigationStatusUpdatePeriodFollowingDecisionInCase_019f703d-e7f8-7e7d-b20f-094b318e4942" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNewClaimsFiledNumber_019e03cb-12d9-7962-83a7-8d612d4a8a61" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyNewClaimsFiledNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_us-gaap_LossContingencyNewClaimsFiledNumber_019e03cb-12d9-7962-83a7-8d612d4a8a61" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualAtCarryingValue_019e03cb-12d9-7d64-aaba-4573850e288c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyAccrualAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_us-gaap_LossContingencyAccrualAtCarryingValue_019e03cb-12d9-7d64-aaba-4573850e288c" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_LossContingencyDamagesSoughtValuePerIndividual_019e03cb-12d9-76a8-9017-2d8209b5879f" xlink:href="meta-20260630.xsd#meta_LossContingencyDamagesSoughtValuePerIndividual"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_meta_LossContingencyDamagesSoughtValuePerIndividual_019e03cb-12d9-76a8-9017-2d8209b5879f" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNumberOfPlaintiffs_019e03cb-12d9-7e1c-ba1e-3fb872fd8236" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyNumberOfPlaintiffs"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_us-gaap_LossContingencyNumberOfPlaintiffs_019e03cb-12d9-7e1c-ba1e-3fb872fd8236" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_LossContingencyNumberOfEntitiesThatFiledAClaim_019e03cb-12d9-7ea7-a14a-e12570439ffe" xlink:href="meta-20260630.xsd#meta_LossContingencyNumberOfEntitiesThatFiledAClaim"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_meta_LossContingencyNumberOfEntitiesThatFiledAClaim_019e03cb-12d9-7ea7-a14a-e12570439ffe" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_LossContingencyNumberOfAdditionalPlaintiffsThatIntervened_019fa384-0ceb-719a-b1b0-d9a13ddd9c68" xlink:href="meta-20260630.xsd#meta_LossContingencyNumberOfAdditionalPlaintiffsThatIntervened"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_meta_LossContingencyNumberOfAdditionalPlaintiffsThatIntervened_019fa384-0ceb-719a-b1b0-d9a13ddd9c68" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyDamagesAwardedValue_019e03cb-12d9-7fd5-a300-1b236d12931d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyDamagesAwardedValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_us-gaap_LossContingencyDamagesAwardedValue_019e03cb-12d9-7fd5-a300-1b236d12931d" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_LossContingencyImposedFine_019e03cb-12d9-778a-b12d-443f85fbf9da" xlink:href="meta-20260630.xsd#meta_LossContingencyImposedFine"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_meta_LossContingencyImposedFine_019e03cb-12d9-778a-b12d-443f85fbf9da" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_LossContingencyDamagesAwardedPercentage_019e03cb-12d9-75ef-8ea8-0b332bdd03ba" xlink:href="meta-20260630.xsd#meta_LossContingencyDamagesAwardedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_meta_LossContingencyDamagesAwardedPercentage_019e03cb-12d9-75ef-8ea8-0b332bdd03ba" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_NumberOfStateAttorneysGeneralWhoHaveSuedInMultidistrictLitigation_019fa38a-485e-7af2-80e4-9d0a5da7a15f" xlink:href="meta-20260630.xsd#meta_NumberOfStateAttorneysGeneralWhoHaveSuedInMultidistrictLitigation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019e03cb-12d8-7204-8da0-3284e22b746e" xlink:to="loc_meta_NumberOfStateAttorneysGeneralWhoHaveSuedInMultidistrictLitigation_019fa38a-485e-7af2-80e4-9d0a5da7a15f" xlink:type="arc" order="23"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/StockholdersEquityCapitalReturnProgramDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#StockholdersEquityCapitalReturnProgramDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/StockholdersEquityCapitalReturnProgramDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-75aa-8193-6f767bc68d48" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-724e-8471-fd121f6a1d5a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-75aa-8193-6f767bc68d48" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-724e-8471-fd121f6a1d5a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramAxis_019e03cb-12d9-79bc-ab47-6c8c91481ea2" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-724e-8471-fd121f6a1d5a" xlink:to="loc_srt_ShareRepurchaseProgramAxis_019e03cb-12d9-79bc-ab47-6c8c91481ea2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_019e03cb-12d9-79bc-ab47-6c8c91481ea2_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ShareRepurchaseProgramAxis_019e03cb-12d9-79bc-ab47-6c8c91481ea2" xlink:to="loc_srt_ShareRepurchaseProgramDomain_019e03cb-12d9-79bc-ab47-6c8c91481ea2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_019e03cb-12d9-712d-930d-853a87fe6baf" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ShareRepurchaseProgramAxis_019e03cb-12d9-79bc-ab47-6c8c91481ea2" xlink:to="loc_srt_ShareRepurchaseProgramDomain_019e03cb-12d9-712d-930d-853a87fe6baf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_January2017ShareRepurchaseProgramMember_019e03cb-12d9-786b-ac8a-33ec599585ce" xlink:href="meta-20260630.xsd#meta_January2017ShareRepurchaseProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_019e03cb-12d9-712d-930d-853a87fe6baf" xlink:to="loc_meta_January2017ShareRepurchaseProgramMember_019e03cb-12d9-786b-ac8a-33ec599585ce" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_019e03cb-12d9-7406-a7b4-b5ee1ef39806" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-75aa-8193-6f767bc68d48" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_019e03cb-12d9-7406-a7b4-b5ee1ef39806" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/StockholdersEquityScheduleofDividenddividendEquivalentActivityDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#StockholdersEquityScheduleofDividenddividendEquivalentActivityDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/StockholdersEquityScheduleofDividenddividendEquivalentActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableLineItems_019e03cb-12d9-7f86-abab-78bc82994f3d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsPayableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableTable_019e03cb-12d9-7f36-acea-a59ad5fb8e86" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsPayableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DividendsPayableLineItems_019e03cb-12d9-7f86-abab-78bc82994f3d" xlink:to="loc_us-gaap_DividendsPayableTable_019e03cb-12d9-7f36-acea-a59ad5fb8e86" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019e03cb-12d9-7d06-9a2e-e68b3deb68b4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DividendsPayableTable_019e03cb-12d9-7f36-acea-a59ad5fb8e86" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019e03cb-12d9-7d06-9a2e-e68b3deb68b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e03cb-12d9-7d06-9a2e-e68b3deb68b4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e03cb-12d9-7d06-9a2e-e68b3deb68b4" xlink:to="loc_us-gaap_ClassOfStockDomain_019e03cb-12d9-7d06-9a2e-e68b3deb68b4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e03cb-12d9-7002-a592-384148a2971d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e03cb-12d9-7d06-9a2e-e68b3deb68b4" xlink:to="loc_us-gaap_ClassOfStockDomain_019e03cb-12d9-7002-a592-384148a2971d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019e03cb-12d9-747b-97e3-d832aa03e12f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019e03cb-12d9-7002-a592-384148a2971d" xlink:to="loc_us-gaap_CommonClassAMember_019e03cb-12d9-747b-97e3-d832aa03e12f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019e03cb-12d9-7d97-9bca-17e0989e0b9a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019e03cb-12d9-7002-a592-384148a2971d" xlink:to="loc_us-gaap_CommonClassBMember_019e03cb-12d9-7d97-9bca-17e0989e0b9a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_019e03cb-12d9-7512-a332-638fba0f55ba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockDividendsPerShareDeclared"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsPayableLineItems_019e03cb-12d9-7f86-abab-78bc82994f3d" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_019e03cb-12d9-7512-a332-638fba0f55ba" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividendsCommonStock_019e03cb-12d9-709b-96be-5787f4da8173" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfDividendsCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsPayableLineItems_019e03cb-12d9-7f86-abab-78bc82994f3d" xlink:to="loc_us-gaap_PaymentsOfDividendsCommonStock_019e03cb-12d9-709b-96be-5787f4da8173" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/StockholdersEquitySharebasedCompensationPlansDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#StockholdersEquitySharebasedCompensationPlansDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/StockholdersEquitySharebasedCompensationPlansDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-7833-bb53-87dd3b82153e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-783b-a96e-b7c12cbe207c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-7833-bb53-87dd3b82153e" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-783b-a96e-b7c12cbe207c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_019e03cb-12d9-7f04-af95-d01f8033e8bf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-783b-a96e-b7c12cbe207c" xlink:to="loc_us-gaap_PlanNameAxis_019e03cb-12d9-7f04-af95-d01f8033e8bf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019e03cb-12d9-7f04-af95-d01f8033e8bf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_019e03cb-12d9-7f04-af95-d01f8033e8bf" xlink:to="loc_us-gaap_PlanNameDomain_019e03cb-12d9-7f04-af95-d01f8033e8bf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019e03cb-12d9-70fd-aa47-279634825c5c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_019e03cb-12d9-7f04-af95-d01f8033e8bf" xlink:to="loc_us-gaap_PlanNameDomain_019e03cb-12d9-70fd-aa47-279634825c5c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_EquityIncentivePlan2025Member_019e03cb-12d9-7742-b970-1c6cface193d" xlink:href="meta-20260630.xsd#meta_EquityIncentivePlan2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019e03cb-12d9-70fd-aa47-279634825c5c" xlink:to="loc_meta_EquityIncentivePlan2025Member_019e03cb-12d9-7742-b970-1c6cface193d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_CommonStockIncreaseInCapitalSharesReservedForFutureIssuance_019e03cb-12d9-788a-8e21-aa8e1995aacc" xlink:href="meta-20260630.xsd#meta_CommonStockIncreaseInCapitalSharesReservedForFutureIssuance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-7833-bb53-87dd3b82153e" xlink:to="loc_meta_CommonStockIncreaseInCapitalSharesReservedForFutureIssuance_019e03cb-12d9-788a-8e21-aa8e1995aacc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_019e03cb-12d9-7d1b-aa2a-dd0a6bf3b3d9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-7833-bb53-87dd3b82153e" xlink:to="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_019e03cb-12d9-7d1b-aa2a-dd0a6bf3b3d9" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/StockholdersEquitySummaryofShareBasedCompensationExpenseDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#StockholdersEquitySummaryofShareBasedCompensationExpenseDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/StockholdersEquitySummaryofShareBasedCompensationExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-754d-8c80-e89c8da9396b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-72ee-9fba-7e5e50989762" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-754d-8c80-e89c8da9396b" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-72ee-9fba-7e5e50989762" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019e03cb-12d9-7df8-a649-52d972020071" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfIncomeLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-72ee-9fba-7e5e50989762" xlink:to="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019e03cb-12d9-7df8-a649-52d972020071" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019e03cb-12d9-70e8-91b2-59dfef782ffa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-72ee-9fba-7e5e50989762" xlink:to="loc_us-gaap_AwardTypeAxis_019e03cb-12d9-70e8-91b2-59dfef782ffa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-70e8-91b2-59dfef782ffa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019e03cb-12d9-70e8-91b2-59dfef782ffa" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-70e8-91b2-59dfef782ffa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-7210-b1e5-28f29cad96f5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019e03cb-12d9-70e8-91b2-59dfef782ffa" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-7210-b1e5-28f29cad96f5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019e03cb-12d9-7645-b841-8c91fb514168" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-7210-b1e5-28f29cad96f5" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019e03cb-12d9-7645-b841-8c91fb514168" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e03cb-12d9-7c7a-bef9-0bdfd6a74339" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-754d-8c80-e89c8da9396b" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e03cb-12d9-7c7a-bef9-0bdfd6a74339" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/StockholdersEquitySummaryofShareBasedCompensationExpenseDetails_1" xlink:type="simple" xlink:href="meta-20260630.xsd#StockholdersEquitySummaryofShareBasedCompensationExpenseDetails_1"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/StockholdersEquitySummaryofShareBasedCompensationExpenseDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-754d-8c80-e89c8da9396b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-72ee-9fba-7e5e50989762" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-754d-8c80-e89c8da9396b" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-72ee-9fba-7e5e50989762" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019e03cb-12d9-70e8-91b2-59dfef782ffa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-72ee-9fba-7e5e50989762" xlink:to="loc_us-gaap_AwardTypeAxis_019e03cb-12d9-70e8-91b2-59dfef782ffa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-70e8-91b2-59dfef782ffa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019e03cb-12d9-70e8-91b2-59dfef782ffa" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-70e8-91b2-59dfef782ffa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-7210-b1e5-28f29cad96f5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019e03cb-12d9-70e8-91b2-59dfef782ffa" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-7210-b1e5-28f29cad96f5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019e03cb-12d9-7645-b841-8c91fb514168" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-7210-b1e5-28f29cad96f5" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019e03cb-12d9-7645-b841-8c91fb514168" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e03cb-12d9-7c7a-bef9-0bdfd6a74339" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-754d-8c80-e89c8da9396b" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e03cb-12d9-7c7a-bef9-0bdfd6a74339" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/StockholdersEquityRestrictedStockUnitsDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#StockholdersEquityRestrictedStockUnitsDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/StockholdersEquityRestrictedStockUnitsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-7a45-a9ef-fa0a3b665f41" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-743e-a560-5612c2b62151" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-7a45-a9ef-fa0a3b665f41" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-743e-a560-5612c2b62151" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019e03cb-12d9-7616-a741-2160698adf61" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-743e-a560-5612c2b62151" xlink:to="loc_us-gaap_AwardTypeAxis_019e03cb-12d9-7616-a741-2160698adf61" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-7616-a741-2160698adf61_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019e03cb-12d9-7616-a741-2160698adf61" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-7616-a741-2160698adf61_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-7da5-9b52-67b006b97d06" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019e03cb-12d9-7616-a741-2160698adf61" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-7da5-9b52-67b006b97d06" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019e03cb-12d9-7055-9fe6-82a0b9fe9752" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-7da5-9b52-67b006b97d06" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019e03cb-12d9-7055-9fe6-82a0b9fe9752" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019e03cb-12d9-757a-ab4e-2dfd610099c8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-7a45-a9ef-fa0a3b665f41" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019e03cb-12d9-757a-ab4e-2dfd610099c8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019e03cb-12d9-77d2-94b8-7f4499f7c756" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019e03cb-12d9-757a-ab4e-2dfd610099c8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019e03cb-12d9-77d2-94b8-7f4499f7c756" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019e03cb-12d9-73ca-aaec-887be53d1226" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019e03cb-12d9-757a-ab4e-2dfd610099c8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019e03cb-12d9-73ca-aaec-887be53d1226" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019e03cb-12d9-7ec2-a789-0162bd2599d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019e03cb-12d9-757a-ab4e-2dfd610099c8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019e03cb-12d9-7ec2-a789-0162bd2599d0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019e03cb-12d9-78de-865f-54f565c203b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019e03cb-12d9-757a-ab4e-2dfd610099c8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019e03cb-12d9-78de-865f-54f565c203b9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019e03cb-12d9-72ea-b68b-75a03a34875b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019e03cb-12d9-7b9f-960d-5c9eb05f0c0f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-7a45-a9ef-fa0a3b665f41" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019e03cb-12d9-7b9f-960d-5c9eb05f0c0f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019e03cb-12d9-79c8-b10a-73de7f51aff0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019e03cb-12d9-7b9f-960d-5c9eb05f0c0f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019e03cb-12d9-79c8-b10a-73de7f51aff0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019e03cb-12d9-7ce4-a476-2d7aaea0720d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019e03cb-12d9-7b9f-960d-5c9eb05f0c0f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019e03cb-12d9-7ce4-a476-2d7aaea0720d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019e03cb-12d9-71ef-9a70-80d5c37019b0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019e03cb-12d9-7b9f-960d-5c9eb05f0c0f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019e03cb-12d9-71ef-9a70-80d5c37019b0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019e03cb-12d9-7106-8aff-b40464a437e2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019e03cb-12d9-7b9f-960d-5c9eb05f0c0f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019e03cb-12d9-7106-8aff-b40464a437e2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019e03cb-12d9-79a3-8781-fc5f4358a513" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/StockholdersEquityAdditionalAwardDisclosuresDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#StockholdersEquityAdditionalAwardDisclosuresDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/StockholdersEquityAdditionalAwardDisclosuresDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-701f-b65b-f4e60d27aaec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-7a3b-9e1f-b95e6136eddb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-701f-b65b-f4e60d27aaec" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-7a3b-9e1f-b95e6136eddb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019e03cb-12d9-77a4-ba43-0e594e7504d3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e03cb-12d9-7a3b-9e1f-b95e6136eddb" xlink:to="loc_us-gaap_AwardTypeAxis_019e03cb-12d9-77a4-ba43-0e594e7504d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-77a4-ba43-0e594e7504d3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019e03cb-12d9-77a4-ba43-0e594e7504d3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-77a4-ba43-0e594e7504d3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-73c3-a84b-76e002093181" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019e03cb-12d9-77a4-ba43-0e594e7504d3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-73c3-a84b-76e002093181" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019e03cb-12d9-71da-8a57-132082b9d170" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-73c3-a84b-76e002093181" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019e03cb-12d9-71da-8a57-132082b9d170" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019e03cb-12d9-737c-81b5-a3cde2211398" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e03cb-12d9-73c3-a84b-76e002093181" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019e03cb-12d9-737c-81b5-a3cde2211398" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_019e03cb-12d9-7641-a70e-784b679aeb0a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-701f-b65b-f4e60d27aaec" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_019e03cb-12d9-7641-a70e-784b679aeb0a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_019e03cb-12d9-72f7-b4c0-ed2af8487e1a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-701f-b65b-f4e60d27aaec" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_019e03cb-12d9-72f7-b4c0-ed2af8487e1a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_019e03cb-12d9-78f9-9587-6cc123405a5a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-701f-b65b-f4e60d27aaec" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_019e03cb-12d9-78f9-9587-6cc123405a5a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019e03cb-12d9-7e6a-b2f1-4a30e273f2e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-701f-b65b-f4e60d27aaec" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019e03cb-12d9-7e6a-b2f1-4a30e273f2e1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_019e03cb-12d9-7f11-a99b-6054851d8a71" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-701f-b65b-f4e60d27aaec" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_019e03cb-12d9-7f11-a99b-6054851d8a71" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_019e03cb-12d9-7324-a794-3c164193e90c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-701f-b65b-f4e60d27aaec" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_019e03cb-12d9-7324-a794-3c164193e90c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_019e03cb-12d9-7f18-a7f9-096273cacc85" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-701f-b65b-f4e60d27aaec" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_019e03cb-12d9-7f18-a7f9-096273cacc85" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_019e03cb-12d9-75fb-ae77-1c019867c806" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e03cb-12d9-701f-b65b-f4e60d27aaec" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_019e03cb-12d9-75fb-ae77-1c019867c806" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/IncomeTaxesDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#IncomeTaxesDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/IncomeTaxesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxContingencyLineItems_019e03cb-12d9-71c9-9b94-efbbc5e392c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxContingencyLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxContingencyTable_019e03cb-12d9-786f-a6cb-f4879b58b578" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxContingencyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019e03cb-12d9-71c9-9b94-efbbc5e392c4" xlink:to="loc_us-gaap_IncomeTaxContingencyTable_019e03cb-12d9-786f-a6cb-f4879b58b578" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameAxis_019e03cb-12d9-724c-91ae-c828d09e8e33" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxAuthorityNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxContingencyTable_019e03cb-12d9-786f-a6cb-f4879b58b578" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameAxis_019e03cb-12d9-724c-91ae-c828d09e8e33" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameDomain_019e03cb-12d9-724c-91ae-c828d09e8e33_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxAuthorityNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameAxis_019e03cb-12d9-724c-91ae-c828d09e8e33" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameDomain_019e03cb-12d9-724c-91ae-c828d09e8e33_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameDomain_019e03cb-12d9-7ea1-9cc6-9c9512feb206" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxAuthorityNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameAxis_019e03cb-12d9-724c-91ae-c828d09e8e33" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameDomain_019e03cb-12d9-7ea1-9cc6-9c9512feb206" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalRevenueServiceIRSMember_019e03cb-12d9-7dc8-be61-a8f1f217a1f1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InternalRevenueServiceIRSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameDomain_019e03cb-12d9-7ea1-9cc6-9c9512feb206" xlink:to="loc_us-gaap_InternalRevenueServiceIRSMember_019e03cb-12d9-7dc8-be61-a8f1f217a1f1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefits_019e03cb-12d9-7c41-9f7e-9e2b996046d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrecognizedTaxBenefits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019e03cb-12d9-71c9-9b94-efbbc5e392c4" xlink:to="loc_us-gaap_UnrecognizedTaxBenefits_019e03cb-12d9-7c41-9f7e-9e2b996046d0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_019e03cb-12d9-78a9-83ef-38b173397f41" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019e03cb-12d9-71c9-9b94-efbbc5e392c4" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_019e03cb-12d9-78a9-83ef-38b173397f41" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExaminationPenaltiesAndInterestAccrued_019e03cb-12d9-7e14-bb37-569f351de9c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExaminationPenaltiesAndInterestAccrued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019e03cb-12d9-71c9-9b94-efbbc5e392c4" xlink:to="loc_us-gaap_IncomeTaxExaminationPenaltiesAndInterestAccrued_019e03cb-12d9-7e14-bb37-569f351de9c0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_019f7046-e57a-7049-ac50-6e1254a14a32" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019e03cb-12d9-71c9-9b94-efbbc5e392c4" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_019f7046-e57a-7049-ac50-6e1254a14a32" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_IncomeTaxExpenseBenefitDiscreteChargeRelatedToNewLegislation_019f7049-d27d-7805-97c4-a9eac85f4ed0" xlink:href="meta-20260630.xsd#meta_IncomeTaxExpenseBenefitDiscreteChargeRelatedToNewLegislation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019e03cb-12d9-71c9-9b94-efbbc5e392c4" xlink:to="loc_meta_IncomeTaxExpenseBenefitDiscreteChargeRelatedToNewLegislation_019f7049-d27d-7805-97c4-a9eac85f4ed0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_IncomeTaxExaminationIntangibleAssetsTransferredToSubsidiaryValue_019e03cb-12d9-768d-a719-3ece2520abb0" xlink:href="meta-20260630.xsd#meta_IncomeTaxExaminationIntangibleAssetsTransferredToSubsidiaryValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019e03cb-12d9-71c9-9b94-efbbc5e392c4" xlink:to="loc_meta_IncomeTaxExaminationIntangibleAssetsTransferredToSubsidiaryValue_019e03cb-12d9-768d-a719-3ece2520abb0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_IncomeTaxExaminationIntangibleAssetsTransferredToSubsidiaryIncreaseInReportedValue_019e03cb-12d9-724e-a4d5-56c088305fd2" xlink:href="meta-20260630.xsd#meta_IncomeTaxExaminationIntangibleAssetsTransferredToSubsidiaryIncreaseInReportedValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019e03cb-12d9-71c9-9b94-efbbc5e392c4" xlink:to="loc_meta_IncomeTaxExaminationIntangibleAssetsTransferredToSubsidiaryIncreaseInReportedValue_019e03cb-12d9-724e-a4d5-56c088305fd2" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExaminationEstimateOfPossibleLoss_019e03cb-12d9-79f3-9831-15107aac41d9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExaminationEstimateOfPossibleLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019e03cb-12d9-71c9-9b94-efbbc5e392c4" xlink:to="loc_us-gaap_IncomeTaxExaminationEstimateOfPossibleLoss_019e03cb-12d9-79f3-9831-15107aac41d9" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/SegmentInformationSegmentInformationofRevenueandIncomeDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#SegmentInformationSegmentInformationofRevenueandIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/SegmentInformationSegmentInformationofRevenueandIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019e03cb-12d9-7b2b-8c35-828302263f59" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e03cb-12d9-76e7-ba12-b669ee0de47f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e03cb-12d9-7b2b-8c35-828302263f59" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e03cb-12d9-76e7-ba12-b669ee0de47f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019e03cb-12d9-7a08-aa40-d781f89dd29c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019e03cb-12d9-76e7-ba12-b669ee0de47f" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019e03cb-12d9-7a08-aa40-d781f89dd29c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019e03cb-12d9-7a08-aa40-d781f89dd29c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019e03cb-12d9-7a08-aa40-d781f89dd29c" xlink:to="loc_us-gaap_SegmentDomain_019e03cb-12d9-7a08-aa40-d781f89dd29c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019e03cb-12d9-7538-a55f-d07ddecdd816" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019e03cb-12d9-7a08-aa40-d781f89dd29c" xlink:to="loc_us-gaap_SegmentDomain_019e03cb-12d9-7538-a55f-d07ddecdd816" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_FamilyOfAppsMember_019e03cb-12d9-71ea-a2d3-f8c293f7e61d" xlink:href="meta-20260630.xsd#meta_FamilyOfAppsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019e03cb-12d9-7538-a55f-d07ddecdd816" xlink:to="loc_meta_FamilyOfAppsMember_019e03cb-12d9-71ea-a2d3-f8c293f7e61d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_RealityLabsMember_019e03cb-12d9-7bd6-a765-1677f777c1f7" xlink:href="meta-20260630.xsd#meta_RealityLabsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019e03cb-12d9-7538-a55f-d07ddecdd816" xlink:to="loc_meta_RealityLabsMember_019e03cb-12d9-7bd6-a765-1677f777c1f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e03cb-12d9-7e8f-8f6f-83448f77a346" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e03cb-12d9-7b2b-8c35-828302263f59" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e03cb-12d9-7e8f-8f6f-83448f77a346" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LaborAndRelatedExpense_019e03cb-12d9-7515-868b-f9d8cdcdeff2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LaborAndRelatedExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e03cb-12d9-7b2b-8c35-828302263f59" xlink:to="loc_us-gaap_LaborAndRelatedExpense_019e03cb-12d9-7515-868b-f9d8cdcdeff2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCostAndExpenseOperating_019e03cb-12d9-7ffc-92f1-a53574003da0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCostAndExpenseOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e03cb-12d9-7b2b-8c35-828302263f59" xlink:to="loc_us-gaap_OtherCostAndExpenseOperating_019e03cb-12d9-7ffc-92f1-a53574003da0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019e03cb-12d9-7fd1-938d-5fddade70a6b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e03cb-12d9-7b2b-8c35-828302263f59" xlink:to="loc_us-gaap_OperatingIncomeLoss_019e03cb-12d9-7fd1-938d-5fddade70a6b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeveranceCosts1_019f7feb-1f20-7099-b1d1-9ba60a0228cc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeveranceCosts1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e03cb-12d9-7b2b-8c35-828302263f59" xlink:to="loc_us-gaap_SeveranceCosts1_019f7feb-1f20-7099-b1d1-9ba60a0228cc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_ReductionInWorkforceNumberOfPositionsEliminated_019f8152-8e75-717f-ae81-d5f963ec063d" xlink:href="meta-20260630.xsd#meta_ReductionInWorkforceNumberOfPositionsEliminated"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019e03cb-12d9-7b2b-8c35-828302263f59" xlink:to="loc_meta_ReductionInWorkforceNumberOfPositionsEliminated_019f8152-8e75-717f-ae81-d5f963ec063d" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.facebook.com/role/SubsequentEventDetails" xlink:type="simple" xlink:href="meta-20260630.xsd#SubsequentEventDetails"/>
  <link:definitionLink xlink:role="http://www.facebook.com/role/SubsequentEventDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_019e03cb-12d9-70d4-bc38-0dd2c59f440e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_019e03cb-12d9-743b-b041-ef914f72b8dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_019e03cb-12d9-70d4-bc38-0dd2c59f440e" xlink:to="loc_us-gaap_SubsequentEventTable_019e03cb-12d9-743b-b041-ef914f72b8dc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019e03cb-12d9-7896-9509-86f4f0208cfd" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019e03cb-12d9-743b-b041-ef914f72b8dc" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019e03cb-12d9-7896-9509-86f4f0208cfd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019e03cb-12d9-7896-9509-86f4f0208cfd_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019e03cb-12d9-7896-9509-86f4f0208cfd" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019e03cb-12d9-7896-9509-86f4f0208cfd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019e03cb-12d9-7b62-a210-ed30b2c22704" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019e03cb-12d9-7896-9509-86f4f0208cfd" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019e03cb-12d9-7b62-a210-ed30b2c22704" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_DataCenterCampusInTexasMember_019eb665-007d-7bd4-88ee-06ff22710e38" xlink:href="meta-20260630.xsd#meta_DataCenterCampusInTexasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_019e03cb-12d9-7b62-a210-ed30b2c22704" xlink:to="loc_meta_DataCenterCampusInTexasMember_019eb665-007d-7bd4-88ee-06ff22710e38" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019faa00-ba87-7cb7-8fed-d300fafa5657" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019e03cb-12d9-743b-b041-ef914f72b8dc" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019faa00-ba87-7cb7-8fed-d300fafa5657" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019faa00-ba87-7cb7-8fed-d300fafa5657_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019faa00-ba87-7cb7-8fed-d300fafa5657" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019faa00-ba87-7cb7-8fed-d300fafa5657_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019faa00-ba87-78b6-89e0-c5c20886e039" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019faa00-ba87-7cb7-8fed-d300fafa5657" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019faa00-ba87-78b6-89e0-c5c20886e039" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019faa00-ce34-7c65-8bfc-cb50c20cc1dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019faa00-ba87-78b6-89e0-c5c20886e039" xlink:to="loc_us-gaap_SubsequentEventMember_019faa00-ce34-7c65-8bfc-cb50c20cc1dc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementScenarioAxis_019faa99-2653-736d-b8aa-85a97481e350" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StatementScenarioAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019e03cb-12d9-743b-b041-ef914f72b8dc" xlink:to="loc_srt_StatementScenarioAxis_019faa99-2653-736d-b8aa-85a97481e350" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_019faa99-2653-736d-b8aa-85a97481e350_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementScenarioAxis_019faa99-2653-736d-b8aa-85a97481e350" xlink:to="loc_srt_ScenarioUnspecifiedDomain_019faa99-2653-736d-b8aa-85a97481e350_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_019faa99-2653-755f-8fb3-7574bbf99a74" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementScenarioAxis_019faa99-2653-736d-b8aa-85a97481e350" xlink:to="loc_srt_ScenarioUnspecifiedDomain_019faa99-2653-755f-8fb3-7574bbf99a74" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioForecastMember_019faa99-3b4b-72e2-a520-d48cf6f9958f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScenarioForecastMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ScenarioUnspecifiedDomain_019faa99-2653-755f-8fb3-7574bbf99a74" xlink:to="loc_srt_ScenarioForecastMember_019faa99-3b4b-72e2-a520-d48cf6f9958f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_019faa99-5069-7ffe-aa5c-3e2ab537eaa7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019e03cb-12d9-70d4-bc38-0dd2c59f440e" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_019faa99-5069-7ffe-aa5c-3e2ab537eaa7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_AssetsAndLiabilitiesHeldForSaleNetContributedToJointVenture_019faa99-8161-71c2-b55e-c24afb11c381" xlink:href="meta-20260630.xsd#meta_AssetsAndLiabilitiesHeldForSaleNetContributedToJointVenture"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019e03cb-12d9-70d4-bc38-0dd2c59f440e" xlink:to="loc_meta_AssetsAndLiabilitiesHeldForSaleNetContributedToJointVenture_019faa99-8161-71c2-b55e-c24afb11c381" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_VentureOneTimeDistribution_019faa99-9deb-7683-b6b2-124c557caf7a" xlink:href="meta-20260630.xsd#meta_VentureOneTimeDistribution"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019e03cb-12d9-70d4-bc38-0dd2c59f440e" xlink:to="loc_meta_VentureOneTimeDistribution_019faa99-9deb-7683-b6b2-124c557caf7a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_UnrecordedUnconditionalPurchaseObligationResidualValueGuaranteeMaximum_019faa99-c055-7904-a8d9-3e9fdb1ebfd4" xlink:href="meta-20260630.xsd#meta_UnrecordedUnconditionalPurchaseObligationResidualValueGuaranteeMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019e03cb-12d9-70d4-bc38-0dd2c59f440e" xlink:to="loc_meta_UnrecordedUnconditionalPurchaseObligationResidualValueGuaranteeMaximum_019faa99-c055-7904-a8d9-3e9fdb1ebfd4" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2026/ecd-2026.xsd#IndividualsOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ecd_AllIndividualsMember" xlink:href="https://xbrl.sec.gov/ecd/2026/ecd-2026.xsd#ecd_AllIndividualsMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_ChristopherK.CoxMember_019eb37b-7a77-7d16-974b-2cd8959556c9" xlink:href="meta-20260630.xsd#meta_ChristopherK.CoxMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_meta_ChristopherK.CoxMember_019eb37b-7a77-7d16-974b-2cd8959556c9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_AaronAndersonMember_019e03cb-1123-7950-b2ac-9945e924b509" xlink:href="meta-20260630.xsd#meta_AaronAndersonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_meta_AaronAndersonMember_019e03cb-1123-7950-b2ac-9945e924b509" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/TradingArrangementsOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2026/ecd-2026.xsd#TradingArrangmentsOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/ecd/role/TradingArrangementsOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ecd_AllTradingArrangementsMember" xlink:href="https://xbrl.sec.gov/ecd/2026/ecd-2026.xsd#ecd_AllTradingArrangementsMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_AaronAndersonFebruary2026TradingArrangementMember_019eb382-6b15-71a8-a7cc-53ac684fc1d5" xlink:href="meta-20260630.xsd#meta_AaronAndersonFebruary2026TradingArrangementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllTradingArrangementsMember" xlink:to="loc_meta_AaronAndersonFebruary2026TradingArrangementMember_019eb382-6b15-71a8-a7cc-53ac684fc1d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_meta_AaronAndersonMay2026TradingArrangementMember_019eb382-e339-74ba-b914-3465d087d1ec" xlink:href="meta-20260630.xsd#meta_AaronAndersonMay2026TradingArrangementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllTradingArrangementsMember" xlink:to="loc_meta_AaronAndersonMay2026TradingArrangementMember_019eb382-e339-74ba-b914-3465d087d1ec" xlink:type="arc" order="2"/>
  </link:definitionLink>
</link:linkbase>
