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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019cd9de-1599-7721-9c44-3f0ec9676e4c,g:780d85fd-7133-4ced-a45b-09359b048e7e-->
<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://ringcentral.com/role/CoverPage" xlink:type="simple" xlink:href="rng-20260331.xsd#CoverPage"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/CoverPage" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable_019cd9de-1653-7b3b-ad5b-c4394c2eaf94" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_DocumentInformationTable_019cd9de-1653-7b3b-ad5b-c4394c2eaf94" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019cd9de-1653-7358-9570-b2bbead10229" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_019cd9de-1653-7b3b-ad5b-c4394c2eaf94" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019cd9de-1653-7358-9570-b2bbead10229" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019cd9de-1653-7358-9570-b2bbead10229_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019cd9de-1653-7358-9570-b2bbead10229" xlink:to="loc_us-gaap_ClassOfStockDomain_019cd9de-1653-7358-9570-b2bbead10229_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019cd9de-1653-754c-ade6-d8813767f4ab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019cd9de-1653-7358-9570-b2bbead10229" xlink:to="loc_us-gaap_ClassOfStockDomain_019cd9de-1653-754c-ade6-d8813767f4ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019cd9de-1653-7e71-8cef-380e2bb93906" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019cd9de-1653-754c-ade6-d8813767f4ab" xlink:to="loc_us-gaap_CommonClassAMember_019cd9de-1653-7e71-8cef-380e2bb93906" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019cd9de-1653-7163-8f60-865c061e584c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019cd9de-1653-754c-ade6-d8813767f4ab" xlink:to="loc_us-gaap_CommonClassBMember_019cd9de-1653-7163-8f60-865c061e584c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_019cd9de-1653-7ebb-a342-91b0e55768fa" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_DocumentType_019cd9de-1653-7ebb-a342-91b0e55768fa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentQuarterlyReport_019cd9de-1653-7564-8670-cff1e4a83a6c" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentQuarterlyReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_DocumentQuarterlyReport_019cd9de-1653-7564-8670-cff1e4a83a6c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_019cd9de-1653-7a24-898c-c9011cbb22ae" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_DocumentPeriodEndDate_019cd9de-1653-7a24-898c-c9011cbb22ae" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_019cd9de-1653-7c8d-93a6-17df12ae274b" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_DocumentTransitionReport_019cd9de-1653-7c8d-93a6-17df12ae274b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_019cd9de-1653-7da4-ab49-66fcd575cfcf" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_EntityFileNumber_019cd9de-1653-7da4-ab49-66fcd575cfcf" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_019cd9de-1653-7cdc-8624-131f06db14a2" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_EntityRegistrantName_019cd9de-1653-7cdc-8624-131f06db14a2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_019cd9de-1653-7b52-b915-b93c5c514531" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_EntityIncorporationStateCountryCode_019cd9de-1653-7b52-b915-b93c5c514531" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_019cd9de-1653-7fab-a6f7-df182a2d3d8f" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_EntityTaxIdentificationNumber_019cd9de-1653-7fab-a6f7-df182a2d3d8f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_019cd9de-1653-772c-acda-936e20f6fbd2" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_EntityAddressAddressLine1_019cd9de-1653-772c-acda-936e20f6fbd2" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_019cd9de-1653-799d-8eda-59fe32c69fee" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_EntityAddressCityOrTown_019cd9de-1653-799d-8eda-59fe32c69fee" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_019cd9de-1653-7749-a8fa-f246b1221b7e" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_EntityAddressStateOrProvince_019cd9de-1653-7749-a8fa-f246b1221b7e" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_019cd9de-1653-7ca8-8416-7c00016e1150" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_EntityAddressPostalZipCode_019cd9de-1653-7ca8-8416-7c00016e1150" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_019cd9de-1653-7873-a45f-70e4fce90b63" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_CityAreaCode_019cd9de-1653-7873-a45f-70e4fce90b63" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_019cd9de-1653-7795-94db-6c78912c6e0f" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_LocalPhoneNumber_019cd9de-1653-7795-94db-6c78912c6e0f" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_019cd9de-1653-78b9-91f1-24f24cf078a5" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_Security12bTitle_019cd9de-1653-78b9-91f1-24f24cf078a5" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_019cd9de-1653-7e24-8833-5bb4cc22bf19" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_TradingSymbol_019cd9de-1653-7e24-8833-5bb4cc22bf19" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_019cd9de-1653-79b9-afd9-956b88932f02" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_SecurityExchangeName_019cd9de-1653-79b9-afd9-956b88932f02" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_019cd9de-1653-72a8-a829-90b55747cbdb" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_EntityCurrentReportingStatus_019cd9de-1653-72a8-a829-90b55747cbdb" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_019cd9de-1653-766f-80c0-c9a0addf01b7" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_EntityInteractiveDataCurrent_019cd9de-1653-766f-80c0-c9a0addf01b7" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_019cd9de-1653-7671-960c-ea644320c694" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_EntityFilerCategory_019cd9de-1653-7671-960c-ea644320c694" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_019cd9de-1653-7099-bcad-806614fdf61c" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_EntitySmallBusiness_019cd9de-1653-7099-bcad-806614fdf61c" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_019cd9de-1653-7b36-92e6-bd0787a29d20" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_EntityEmergingGrowthCompany_019cd9de-1653-7b36-92e6-bd0787a29d20" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_019cd9de-1653-7326-a861-553b6c42397d" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_EntityShellCompany_019cd9de-1653-7326-a861-553b6c42397d" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_019cd9de-1653-7f71-9edb-f3371f0b8c57" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_019cd9de-1653-7f71-9edb-f3371f0b8c57" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_019cd9de-1653-7ac3-b990-82488b36a902" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_AmendmentFlag_019cd9de-1653-7ac3-b990-82488b36a902" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_019cd9de-1653-7991-abcb-b78a18da663b" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_DocumentFiscalYearFocus_019cd9de-1653-7991-abcb-b78a18da663b" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_019cd9de-1653-797d-b844-34f932e664bf" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_DocumentFiscalPeriodFocus_019cd9de-1653-797d-b844-34f932e664bf" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_019cd9de-1653-78d2-bf07-72fcbfd03b42" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_EntityCentralIndexKey_019cd9de-1653-78d2-bf07-72fcbfd03b42" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_019cd9de-1653-7def-b4df-d75efd7fa2f6" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cd9de-1653-7e12-953d-2b8f088021ac" xlink:to="loc_dei_CurrentFiscalYearEndDate_019cd9de-1653-7def-b4df-d75efd7fa2f6" xlink:type="arc" order="28"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS" xlink:type="simple" xlink:href="rng-20260331.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019cd9de-1706-7914-bbd9-59be0b1f163c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019cd9de-1706-757a-a737-d1d1a7a23a4e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019cd9de-1706-7914-bbd9-59be0b1f163c" xlink:to="loc_us-gaap_StatementTable_019cd9de-1706-757a-a737-d1d1a7a23a4e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019cd9de-1706-74ba-ad87-c1732d0361f3" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019cd9de-1706-757a-a737-d1d1a7a23a4e" xlink:to="loc_srt_ProductOrServiceAxis_019cd9de-1706-74ba-ad87-c1732d0361f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019cd9de-1706-74ba-ad87-c1732d0361f3_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019cd9de-1706-74ba-ad87-c1732d0361f3" xlink:to="loc_srt_ProductsAndServicesDomain_019cd9de-1706-74ba-ad87-c1732d0361f3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7d8e-afeb-c00135d3c7fb" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019cd9de-1706-74ba-ad87-c1732d0361f3" xlink:to="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7d8e-afeb-c00135d3c7fb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LicenseAndServiceMember_019cd9de-1706-7f56-bfc3-d5a0147d12d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LicenseAndServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7d8e-afeb-c00135d3c7fb" xlink:to="loc_us-gaap_LicenseAndServiceMember_019cd9de-1706-7f56-bfc3-d5a0147d12d5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductAndServiceOtherMember_019cd9de-1706-75d2-a5d3-1f5570a41f7f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProductAndServiceOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7d8e-afeb-c00135d3c7fb" xlink:to="loc_us-gaap_ProductAndServiceOtherMember_019cd9de-1706-75d2-a5d3-1f5570a41f7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueAbstract_019cd9de-1706-7037-81a1-83950fb9fb3f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019cd9de-1706-7914-bbd9-59be0b1f163c" xlink:to="loc_us-gaap_DisaggregationOfRevenueAbstract_019cd9de-1706-7037-81a1-83950fb9fb3f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019cd9de-1706-712c-b6bf-705b7efefe5a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueAbstract_019cd9de-1706-7037-81a1-83950fb9fb3f" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019cd9de-1706-712c-b6bf-705b7efefe5a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSoldAbstract_019cd9de-1706-7730-8fe2-27e860eaba9d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSoldAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019cd9de-1706-7914-bbd9-59be0b1f163c" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSoldAbstract_019cd9de-1706-7730-8fe2-27e860eaba9d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_019cd9de-1706-7936-a51a-6656e7cc56e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfGoodsAndServicesSoldAbstract_019cd9de-1706-7730-8fe2-27e860eaba9d" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_019cd9de-1706-7936-a51a-6656e7cc56e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_019cd9de-1706-7f83-a01e-e7bbaaed43c6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019cd9de-1706-7914-bbd9-59be0b1f163c" xlink:to="loc_us-gaap_GrossProfit_019cd9de-1706-7f83-a01e-e7bbaaed43c6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_019cd9de-1706-7d23-a20a-4d6e4829ebe1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019cd9de-1706-7914-bbd9-59be0b1f163c" xlink:to="loc_us-gaap_OperatingExpensesAbstract_019cd9de-1706-7d23-a20a-4d6e4829ebe1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_019cd9de-1706-70f0-a5f6-37923e323ad6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019cd9de-1706-7d23-a20a-4d6e4829ebe1" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_019cd9de-1706-70f0-a5f6-37923e323ad6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpense_019cd9de-1706-729b-8f0c-9174b1a720a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingAndMarketingExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019cd9de-1706-7d23-a20a-4d6e4829ebe1" xlink:to="loc_us-gaap_SellingAndMarketingExpense_019cd9de-1706-729b-8f0c-9174b1a720a9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_019cd9de-1706-7431-99ce-2876ea5e5508" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019cd9de-1706-7d23-a20a-4d6e4829ebe1" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_019cd9de-1706-7431-99ce-2876ea5e5508" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019cd9de-1706-7759-9a96-2e465eff645b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019cd9de-1706-7d23-a20a-4d6e4829ebe1" xlink:to="loc_us-gaap_OperatingExpenses_019cd9de-1706-7759-9a96-2e465eff645b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019cd9de-1706-76fa-ad43-c55a610c3550" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019cd9de-1706-7914-bbd9-59be0b1f163c" xlink:to="loc_us-gaap_OperatingIncomeLoss_019cd9de-1706-76fa-ad43-c55a610c3550" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019cd9de-1706-78c8-af6d-62c42b0f76e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpenseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019cd9de-1706-7914-bbd9-59be0b1f163c" xlink:to="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019cd9de-1706-78c8-af6d-62c42b0f76e8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019cd9de-1706-75dc-9ce2-36f008a303ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019cd9de-1706-78c8-af6d-62c42b0f76e8" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019cd9de-1706-75dc-9ce2-36f008a303ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019cd9de-1706-7f2e-adb9-a059c99268e6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019cd9de-1706-78c8-af6d-62c42b0f76e8" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019cd9de-1706-7f2e-adb9-a059c99268e6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019cd9de-1706-7c2e-aa42-c11465d208e2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019cd9de-1706-78c8-af6d-62c42b0f76e8" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_019cd9de-1706-7c2e-aa42-c11465d208e2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019cd9de-1706-7345-85b6-7229cb5f3a3d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019cd9de-1706-7914-bbd9-59be0b1f163c" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019cd9de-1706-7345-85b6-7229cb5f3a3d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019cd9de-1706-79c2-aae0-5a3e14ca45c2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019cd9de-1706-7914-bbd9-59be0b1f163c" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019cd9de-1706-79c2-aae0-5a3e14ca45c2" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019cd9de-1706-78b6-9eaa-701f8e032b0c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019cd9de-1706-7914-bbd9-59be0b1f163c" xlink:to="loc_us-gaap_NetIncomeLoss_019cd9de-1706-78b6-9eaa-701f8e032b0c" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasicOtherDisclosuresAbstract_019cd9de-1706-791e-a89a-1ea5f19d5218" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareBasicOtherDisclosuresAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019cd9de-1706-7914-bbd9-59be0b1f163c" xlink:to="loc_us-gaap_EarningsPerShareBasicOtherDisclosuresAbstract_019cd9de-1706-791e-a89a-1ea5f19d5218" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_019cd9de-1706-7235-a6c5-3d0d889728ba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicOtherDisclosuresAbstract_019cd9de-1706-791e-a89a-1ea5f19d5218" xlink:to="loc_us-gaap_EarningsPerShareBasic_019cd9de-1706-7235-a6c5-3d0d889728ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_019cd9de-1706-7436-9b10-4f80d919519b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicOtherDisclosuresAbstract_019cd9de-1706-791e-a89a-1ea5f19d5218" xlink:to="loc_us-gaap_EarningsPerShareDiluted_019cd9de-1706-7436-9b10-4f80d919519b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019cd9de-1706-79a5-90e5-2554841c9a14" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019cd9de-1706-7914-bbd9-59be0b1f163c" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019cd9de-1706-79a5-90e5-2554841c9a14" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019cd9de-1706-71ad-af1a-63a6b2ad500b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019cd9de-1706-79a5-90e5-2554841c9a14" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019cd9de-1706-71ad-af1a-63a6b2ad500b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019cd9de-1706-7750-aed2-3db0eef2bb66" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019cd9de-1706-79a5-90e5-2554841c9a14" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019cd9de-1706-7750-aed2-3db0eef2bb66" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSDEFICIT" xlink:type="simple" xlink:href="rng-20260331.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSDEFICIT"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSDEFICIT" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019cd9de-1706-7e8c-8cc4-70ef20bc24e4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019cd9de-1706-732f-a7b6-c1625d37d9e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019cd9de-1706-7e8c-8cc4-70ef20bc24e4" xlink:to="loc_us-gaap_StatementTable_019cd9de-1706-732f-a7b6-c1625d37d9e8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019cd9de-1706-7d01-8081-b873549a5cc8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019cd9de-1706-732f-a7b6-c1625d37d9e8" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019cd9de-1706-7d01-8081-b873549a5cc8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019cd9de-1706-7d01-8081-b873549a5cc8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019cd9de-1706-7d01-8081-b873549a5cc8" xlink:to="loc_us-gaap_EquityComponentDomain_019cd9de-1706-7d01-8081-b873549a5cc8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019cd9de-1706-7891-ba93-16791688d212" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019cd9de-1706-7d01-8081-b873549a5cc8" xlink:to="loc_us-gaap_EquityComponentDomain_019cd9de-1706-7891-ba93-16791688d212" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019cd9de-1706-7911-aeec-1d5ef6243553" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019cd9de-1706-7891-ba93-16791688d212" xlink:to="loc_us-gaap_CommonStockMember_019cd9de-1706-7911-aeec-1d5ef6243553" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019cd9de-1706-703c-afb6-8f8908ea6765" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019cd9de-1706-7891-ba93-16791688d212" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019cd9de-1706-703c-afb6-8f8908ea6765" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019cd9de-1706-7437-bb92-977fa84ad059" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019cd9de-1706-7891-ba93-16791688d212" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019cd9de-1706-7437-bb92-977fa84ad059" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019cd9de-1706-7a4f-a1b9-9bd97163b3d7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019cd9de-1706-7891-ba93-16791688d212" xlink:to="loc_us-gaap_RetainedEarningsMember_019cd9de-1706-7a4f-a1b9-9bd97163b3d7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019cd9de-1706-742d-b8f8-40600fef71e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019cd9de-1706-7e8c-8cc4-70ef20bc24e4" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019cd9de-1706-742d-b8f8-40600fef71e7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019cd9de-1706-784f-bd70-178fbdfab63a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019cd9de-1706-742d-b8f8-40600fef71e7" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019cd9de-1706-784f-bd70-178fbdfab63a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019cd9de-1706-7258-a420-fb4bfc14dbcf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019cd9de-1706-742d-b8f8-40600fef71e7" xlink:to="loc_us-gaap_StockholdersEquity_019cd9de-1706-7258-a420-fb4bfc14dbcf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_019cd9de-1706-73d2-a9b5-99e45e6708da" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019cd9de-1706-742d-b8f8-40600fef71e7" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_019cd9de-1706-73d2-a9b5-99e45e6708da" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_StockIssuedDuringPeriodValueEmployeeStockPurchasePlanIncreaseDecreaseToAdditionalPaidInCapital_019cd9de-1706-7295-ba09-67fb01f429d1" xlink:href="rng-20260331.xsd#rng_StockIssuedDuringPeriodValueEmployeeStockPurchasePlanIncreaseDecreaseToAdditionalPaidInCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019cd9de-1706-742d-b8f8-40600fef71e7" xlink:to="loc_rng_StockIssuedDuringPeriodValueEmployeeStockPurchasePlanIncreaseDecreaseToAdditionalPaidInCapital_019cd9de-1706-7295-ba09-67fb01f429d1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_019cd9de-1706-7553-bcb5-01cc1f819414" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockRepurchasedDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019cd9de-1706-742d-b8f8-40600fef71e7" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_019cd9de-1706-7553-bcb5-01cc1f819414" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_019cd9de-1706-7417-a8ac-ac67d477a4a5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockRepurchasedDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019cd9de-1706-742d-b8f8-40600fef71e7" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_019cd9de-1706-7417-a8ac-ac67d477a4a5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019cd9de-1706-74cc-8bcf-e00a3a73bd68" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019cd9de-1706-742d-b8f8-40600fef71e7" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019cd9de-1706-74cc-8bcf-e00a3a73bd68" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019cd9de-1706-7058-8105-d9ca0662f1c2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019cd9de-1706-742d-b8f8-40600fef71e7" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019cd9de-1706-7058-8105-d9ca0662f1c2" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStockCash_019d3dd4-fdc3-7050-9ba0-c76401f982dc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendsCommonStockCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019cd9de-1706-742d-b8f8-40600fef71e7" xlink:to="loc_us-gaap_DividendsCommonStockCash_019d3dd4-fdc3-7050-9ba0-c76401f982dc" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019cd9de-1706-7069-ab8c-8706bc8fc29a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019cd9de-1706-742d-b8f8-40600fef71e7" xlink:to="loc_us-gaap_NetIncomeLoss_019cd9de-1706-7069-ab8c-8706bc8fc29a" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019cd9de-1706-723f-8c8d-3c98c3f4af9e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019cd9de-1706-7d54-bf74-3e0fbd359a42" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/DescriptionofBusinessandSummaryofSignificantAccountingPoliciesDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#DescriptionofBusinessandSummaryofSignificantAccountingPoliciesDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/DescriptionofBusinessandSummaryofSignificantAccountingPoliciesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_019de365-11c8-73f9-9a32-1393310575a5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019de365-11c8-769c-9781-1408113a7169" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019de365-11c8-73f9-9a32-1393310575a5" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019de365-11c8-769c-9781-1408113a7169" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019de365-11c8-7d3e-b6cc-b57d7d5b0b88" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019de365-11c8-769c-9781-1408113a7169" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019de365-11c8-7d3e-b6cc-b57d7d5b0b88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019de365-11c8-7d3e-b6cc-b57d7d5b0b88_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019de365-11c8-7d3e-b6cc-b57d7d5b0b88" xlink:to="loc_us-gaap_RelatedPartyDomain_019de365-11c8-7d3e-b6cc-b57d7d5b0b88_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019de365-11c8-7005-b86b-63643cb75a8b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019de365-11c8-7d3e-b6cc-b57d7d5b0b88" xlink:to="loc_us-gaap_RelatedPartyDomain_019de365-11c8-7005-b86b-63643cb75a8b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019de365-11c8-78a7-ac4e-d4255b1b8580" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019de365-11c8-7005-b86b-63643cb75a8b" xlink:to="loc_us-gaap_RelatedPartyMember_019de365-11c8-78a7-ac4e-d4255b1b8580" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_019de365-11c8-79de-a466-d6f70bb6cc09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019de365-11c8-73f9-9a32-1393310575a5" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_019de365-11c8-79de-a466-d6f70bb6cc09" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent_019de365-11c8-7ff2-b2ea-3075c255132f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019de365-11c8-73f9-9a32-1393310575a5" xlink:to="loc_us-gaap_AccountsPayableCurrent_019de365-11c8-7ff2-b2ea-3075c255132f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAmountsOfTransaction_019de365-11c8-703b-a783-d6659bcbad36" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionAmountsOfTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019de365-11c8-73f9-9a32-1393310575a5" xlink:to="loc_us-gaap_RelatedPartyTransactionAmountsOfTransaction_019de365-11c8-703b-a783-d6659bcbad36" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/RevenueScheduleofDisaggregatedRevenuebyGeographicalMarketsDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#RevenueScheduleofDisaggregatedRevenuebyGeographicalMarketsDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/RevenueScheduleofDisaggregatedRevenuebyGeographicalMarketsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-774c-bb12-19535fb1c317" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-7c16-9ac4-69ff08cd45db" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-774c-bb12-19535fb1c317" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-7c16-9ac4-69ff08cd45db" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019cd9de-1706-7c4f-8dc1-42f88ad4b403" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-7c16-9ac4-69ff08cd45db" xlink:to="loc_srt_StatementGeographicalAxis_019cd9de-1706-7c4f-8dc1-42f88ad4b403" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019cd9de-1706-7c4f-8dc1-42f88ad4b403_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019cd9de-1706-7c4f-8dc1-42f88ad4b403" xlink:to="loc_srt_SegmentGeographicalDomain_019cd9de-1706-7c4f-8dc1-42f88ad4b403_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019cd9de-1706-7049-8ca3-5701dc4c8ee8" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019cd9de-1706-7c4f-8dc1-42f88ad4b403" xlink:to="loc_srt_SegmentGeographicalDomain_019cd9de-1706-7049-8ca3-5701dc4c8ee8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NorthAmericaMember_019cd9de-1706-735c-9295-7de795f7aa73" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_NorthAmericaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019cd9de-1706-7049-8ca3-5701dc4c8ee8" xlink:to="loc_srt_NorthAmericaMember_019cd9de-1706-735c-9295-7de795f7aa73" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_OtherGeographicalAreaMember_019cd9de-1706-7d4d-a6d7-ab7fcdf6b287" xlink:href="rng-20260331.xsd#rng_OtherGeographicalAreaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019cd9de-1706-7049-8ca3-5701dc4c8ee8" xlink:to="loc_rng_OtherGeographicalAreaMember_019cd9de-1706-7d4d-a6d7-ab7fcdf6b287" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_019cd9de-1706-7f73-a567-fe6acfaf0857" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-7c16-9ac4-69ff08cd45db" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_019cd9de-1706-7f73-a567-fe6acfaf0857" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-1706-7f73-a567-fe6acfaf0857_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019cd9de-1706-7f73-a567-fe6acfaf0857" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-1706-7f73-a567-fe6acfaf0857_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-1706-7287-af84-de42581c2ab3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019cd9de-1706-7f73-a567-fe6acfaf0857" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-1706-7287-af84-de42581c2ab3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicConcentrationRiskMember_019cd9de-1706-7e26-ae31-82a5ae687b8c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeographicConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-1706-7287-af84-de42581c2ab3" xlink:to="loc_us-gaap_GeographicConcentrationRiskMember_019cd9de-1706-7e26-ae31-82a5ae687b8c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019cd9de-1706-7b2f-bb9a-ab665efdd21f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-7c16-9ac4-69ff08cd45db" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019cd9de-1706-7b2f-bb9a-ab665efdd21f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-1706-7b2f-bb9a-ab665efdd21f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019cd9de-1706-7b2f-bb9a-ab665efdd21f" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-1706-7b2f-bb9a-ab665efdd21f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-1706-7307-a993-0db50aa65979" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019cd9de-1706-7b2f-bb9a-ab665efdd21f" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-1706-7307-a993-0db50aa65979" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_019cd9de-1706-7c86-85c8-f86b56c9e300" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-1706-7307-a993-0db50aa65979" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_019cd9de-1706-7c86-85c8-f86b56c9e300" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_019cd9de-1706-7e7b-a5d9-d6e3716225de" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-774c-bb12-19535fb1c317" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_019cd9de-1706-7e7b-a5d9-d6e3716225de" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/RevenueNarrativeDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#RevenueNarrativeDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/RevenueNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-70b7-839b-de8a21992757" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-70b7-839b-de8a21992757" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019cd9de-1706-7a82-9097-b5188075341e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-70b7-839b-de8a21992757" xlink:to="loc_srt_ProductOrServiceAxis_019cd9de-1706-7a82-9097-b5188075341e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7a82-9097-b5188075341e_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019cd9de-1706-7a82-9097-b5188075341e" xlink:to="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7a82-9097-b5188075341e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7600-99c7-5591b4896681" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019cd9de-1706-7a82-9097-b5188075341e" xlink:to="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7600-99c7-5591b4896681" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_RingEXAndRingCentralContactCenterSolutionsMember_019cd9de-1706-7bf7-9307-b4ac8d103f9f" xlink:href="rng-20260331.xsd#rng_RingEXAndRingCentralContactCenterSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7600-99c7-5591b4896681" xlink:to="loc_rng_RingEXAndRingCentralContactCenterSolutionsMember_019cd9de-1706-7bf7-9307-b4ac8d103f9f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_RingCentralContactCenterSolutionsMember_019cd9de-1706-7fa0-afbc-674d29354832" xlink:href="rng-20260331.xsd#rng_RingCentralContactCenterSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7600-99c7-5591b4896681" xlink:to="loc_rng_RingCentralContactCenterSolutionsMember_019cd9de-1706-7fa0-afbc-674d29354832" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_019cd9de-1706-7c3e-ace4-e7244866985a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProductMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7600-99c7-5591b4896681" xlink:to="loc_us-gaap_ProductMember_019cd9de-1706-7c3e-ace4-e7244866985a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019cd9de-1706-7792-9cca-9b488ee81cd5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-70b7-839b-de8a21992757" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019cd9de-1706-7792-9cca-9b488ee81cd5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-1706-7792-9cca-9b488ee81cd5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019cd9de-1706-7792-9cca-9b488ee81cd5" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-1706-7792-9cca-9b488ee81cd5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-1706-74f2-8939-3de470e0815b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019cd9de-1706-7792-9cca-9b488ee81cd5" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-1706-74f2-8939-3de470e0815b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_019cd9de-1706-7db3-967a-ae5107e8104b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-1706-74f2-8939-3de470e0815b" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_019cd9de-1706-7db3-967a-ae5107e8104b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_019cd9de-1706-71b9-88fa-8529f5fb64db" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-70b7-839b-de8a21992757" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_019cd9de-1706-71b9-88fa-8529f5fb64db" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-1706-71b9-88fa-8529f5fb64db_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019cd9de-1706-71b9-88fa-8529f5fb64db" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-1706-71b9-88fa-8529f5fb64db_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-1706-7db5-a97d-96ec94cc1892" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019cd9de-1706-71b9-88fa-8529f5fb64db" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-1706-7db5-a97d-96ec94cc1892" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductConcentrationRiskMember_019cd9de-1706-72fb-ae93-9405c53c08f3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProductConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-1706-7db5-a97d-96ec94cc1892" xlink:to="loc_us-gaap_ProductConcentrationRiskMember_019cd9de-1706-72fb-ae93-9405c53c08f3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019cd9de-1706-7501-9d0e-622378ab9faf" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-70b7-839b-de8a21992757" xlink:to="loc_srt_RangeAxis_019cd9de-1706-7501-9d0e-622378ab9faf" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019cd9de-1706-7501-9d0e-622378ab9faf_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019cd9de-1706-7501-9d0e-622378ab9faf" xlink:to="loc_srt_RangeMember_019cd9de-1706-7501-9d0e-622378ab9faf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019cd9de-1706-7020-b406-362c930baa71" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019cd9de-1706-7501-9d0e-622378ab9faf" xlink:to="loc_srt_RangeMember_019cd9de-1706-7020-b406-362c930baa71" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019cd9de-1706-77ea-b759-e7019a0b14d9" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019cd9de-1706-7020-b406-362c930baa71" xlink:to="loc_srt_MinimumMember_019cd9de-1706-77ea-b759-e7019a0b14d9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019cd9de-1706-7ea6-bc5f-9a341dd9d423" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019cd9de-1706-7020-b406-362c930baa71" xlink:to="loc_srt_MaximumMember_019cd9de-1706-7ea6-bc5f-9a341dd9d423" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_019cd9de-1706-7d66-a766-183b879d3bf9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-70b7-839b-de8a21992757" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_019cd9de-1706-7d66-a766-183b879d3bf9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_019cd9de-1706-7081-897c-40ce53da60e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_019cd9de-1706-7081-897c-40ce53da60e7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_019cd9de-1706-7ef1-8769-d5f3616c612f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_019cd9de-1706-7ef1-8769-d5f3616c612f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_RevenueFromContractWithCustomerSubscriptionTerm_019cd9de-1706-7977-add0-c30522aee3b8" xlink:href="rng-20260331.xsd#rng_RevenueFromContractWithCustomerSubscriptionTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:to="loc_rng_RevenueFromContractWithCustomerSubscriptionTerm_019cd9de-1706-7977-add0-c30522aee3b8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_019cd9de-1706-7a8c-a707-8731d861b942" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_019cd9de-1706-7a8c-a707-8731d861b942" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019cd9de-1706-7fd7-b4b0-c6d018da6ded" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019cd9de-1706-7fd7-b4b0-c6d018da6ded" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019cd9de-1706-7e3a-b3a0-ceddf9cb50ac" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019cd9de-1706-7e3a-b3a0-ceddf9cb50ac" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019cd9de-1706-737c-8bb7-e5e283ad231d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019cd9de-1706-737c-8bb7-e5e283ad231d" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/RevenueNarrativeDetails_1" xlink:type="simple" xlink:href="rng-20260331.xsd#RevenueNarrativeDetails_1"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/RevenueNarrativeDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-70b7-839b-de8a21992757" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-70b7-839b-de8a21992757" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019cd9de-1706-7a82-9097-b5188075341e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-70b7-839b-de8a21992757" xlink:to="loc_srt_ProductOrServiceAxis_019cd9de-1706-7a82-9097-b5188075341e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7a82-9097-b5188075341e_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019cd9de-1706-7a82-9097-b5188075341e" xlink:to="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7a82-9097-b5188075341e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7600-99c7-5591b4896681" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019cd9de-1706-7a82-9097-b5188075341e" xlink:to="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7600-99c7-5591b4896681" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_RingEXAndRingCentralContactCenterSolutionsMember_019cd9de-1706-7bf7-9307-b4ac8d103f9f" xlink:href="rng-20260331.xsd#rng_RingEXAndRingCentralContactCenterSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7600-99c7-5591b4896681" xlink:to="loc_rng_RingEXAndRingCentralContactCenterSolutionsMember_019cd9de-1706-7bf7-9307-b4ac8d103f9f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_RingCentralContactCenterSolutionsMember_019cd9de-1706-7fa0-afbc-674d29354832" xlink:href="rng-20260331.xsd#rng_RingCentralContactCenterSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7600-99c7-5591b4896681" xlink:to="loc_rng_RingCentralContactCenterSolutionsMember_019cd9de-1706-7fa0-afbc-674d29354832" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_019cd9de-1706-7c3e-ace4-e7244866985a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProductMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019cd9de-1706-7600-99c7-5591b4896681" xlink:to="loc_us-gaap_ProductMember_019cd9de-1706-7c3e-ace4-e7244866985a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019cd9de-1706-7792-9cca-9b488ee81cd5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-70b7-839b-de8a21992757" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019cd9de-1706-7792-9cca-9b488ee81cd5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-1706-7792-9cca-9b488ee81cd5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019cd9de-1706-7792-9cca-9b488ee81cd5" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-1706-7792-9cca-9b488ee81cd5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-1706-74f2-8939-3de470e0815b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019cd9de-1706-7792-9cca-9b488ee81cd5" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-1706-74f2-8939-3de470e0815b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_019cd9de-1706-7db3-967a-ae5107e8104b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-1706-74f2-8939-3de470e0815b" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_019cd9de-1706-7db3-967a-ae5107e8104b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_019cd9de-1706-71b9-88fa-8529f5fb64db" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-70b7-839b-de8a21992757" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_019cd9de-1706-71b9-88fa-8529f5fb64db" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-1706-71b9-88fa-8529f5fb64db_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019cd9de-1706-71b9-88fa-8529f5fb64db" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-1706-71b9-88fa-8529f5fb64db_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-1706-7db5-a97d-96ec94cc1892" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019cd9de-1706-71b9-88fa-8529f5fb64db" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-1706-7db5-a97d-96ec94cc1892" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductConcentrationRiskMember_019cd9de-1706-72fb-ae93-9405c53c08f3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProductConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-1706-7db5-a97d-96ec94cc1892" xlink:to="loc_us-gaap_ProductConcentrationRiskMember_019cd9de-1706-72fb-ae93-9405c53c08f3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019cd9de-1706-7501-9d0e-622378ab9faf" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019cd9de-1706-70b7-839b-de8a21992757" xlink:to="loc_srt_RangeAxis_019cd9de-1706-7501-9d0e-622378ab9faf" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019cd9de-1706-7501-9d0e-622378ab9faf_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019cd9de-1706-7501-9d0e-622378ab9faf" xlink:to="loc_srt_RangeMember_019cd9de-1706-7501-9d0e-622378ab9faf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019cd9de-1706-7020-b406-362c930baa71" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019cd9de-1706-7501-9d0e-622378ab9faf" xlink:to="loc_srt_RangeMember_019cd9de-1706-7020-b406-362c930baa71" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019cd9de-1706-77ea-b759-e7019a0b14d9" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019cd9de-1706-7020-b406-362c930baa71" xlink:to="loc_srt_MinimumMember_019cd9de-1706-77ea-b759-e7019a0b14d9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019cd9de-1706-7ea6-bc5f-9a341dd9d423" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019cd9de-1706-7020-b406-362c930baa71" xlink:to="loc_srt_MaximumMember_019cd9de-1706-7ea6-bc5f-9a341dd9d423" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_019cd9de-1706-7081-897c-40ce53da60e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_019cd9de-1706-7081-897c-40ce53da60e7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_019cd9de-1706-7ef1-8769-d5f3616c612f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_019cd9de-1706-7ef1-8769-d5f3616c612f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_RevenueFromContractWithCustomerSubscriptionTerm_019cd9de-1706-7977-add0-c30522aee3b8" xlink:href="rng-20260331.xsd#rng_RevenueFromContractWithCustomerSubscriptionTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:to="loc_rng_RevenueFromContractWithCustomerSubscriptionTerm_019cd9de-1706-7977-add0-c30522aee3b8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_019cd9de-1706-7a8c-a707-8731d861b942" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_019cd9de-1706-7a8c-a707-8731d861b942" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019cd9de-1706-7fd7-b4b0-c6d018da6ded" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019cd9de-1706-7fd7-b4b0-c6d018da6ded" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019cd9de-1706-7e3a-b3a0-ceddf9cb50ac" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019cd9de-1706-7e3a-b3a0-ceddf9cb50ac" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019cd9de-1706-737c-8bb7-e5e283ad231d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019cd9de-1706-77b0-b367-5b728b6abd9a" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019cd9de-1706-737c-8bb7-e5e283ad231d" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/FinancialStatementComponentsScheduleofComponentsofPropertyandEquipmentNetDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#FinancialStatementComponentsScheduleofComponentsofPropertyandEquipmentNetDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/FinancialStatementComponentsScheduleofComponentsofPropertyandEquipmentNetDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019cd9de-1706-73c2-ba81-4102472bb1b9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019cd9de-1706-73b7-9671-7639cc0c198a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019cd9de-1706-73c2-ba81-4102472bb1b9" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019cd9de-1706-73b7-9671-7639cc0c198a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019cd9de-1706-78be-be8a-713089a0de83" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019cd9de-1706-73b7-9671-7639cc0c198a" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019cd9de-1706-78be-be8a-713089a0de83" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019cd9de-1706-78be-be8a-713089a0de83_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019cd9de-1706-78be-be8a-713089a0de83" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019cd9de-1706-78be-be8a-713089a0de83_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019cd9de-1706-7d3b-a0ca-eef86ad9274f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019cd9de-1706-78be-be8a-713089a0de83" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019cd9de-1706-7d3b-a0ca-eef86ad9274f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TechnologyEquipmentMember_019cd9de-1706-7658-808e-186d59073e5b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TechnologyEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019cd9de-1706-7d3b-a0ca-eef86ad9274f" xlink:to="loc_us-gaap_TechnologyEquipmentMember_019cd9de-1706-7658-808e-186d59073e5b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SoftwareDevelopmentMember_019cd9de-1706-7693-b1ce-87bcae88a168" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SoftwareDevelopmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019cd9de-1706-7d3b-a0ca-eef86ad9274f" xlink:to="loc_us-gaap_SoftwareDevelopmentMember_019cd9de-1706-7693-b1ce-87bcae88a168" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_019cd9de-1706-7c26-af0c-5728ea0b9a34" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019cd9de-1706-7d3b-a0ca-eef86ad9274f" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_019cd9de-1706-7c26-af0c-5728ea0b9a34" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_019cd9de-1706-724d-9dd5-ba25a567fe3f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019cd9de-1706-7d3b-a0ca-eef86ad9274f" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_019cd9de-1706-724d-9dd5-ba25a567fe3f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_019cd9de-1706-7ade-9036-53fd9307718a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019cd9de-1706-73c2-ba81-4102472bb1b9" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_019cd9de-1706-7ade-9036-53fd9307718a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019cd9de-1706-71ea-bcad-d5948a9120cc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019cd9de-1706-73c2-ba81-4102472bb1b9" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019cd9de-1706-71ea-bcad-d5948a9120cc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019cd9de-1706-7509-8d53-e7cf3a13ee74" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019cd9de-1706-73c2-ba81-4102472bb1b9" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_019cd9de-1706-7509-8d53-e7cf3a13ee74" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/FinancialStatementComponentsScheduleofCarryingValuesofIntangibleAssetsDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#FinancialStatementComponentsScheduleofCarryingValuesofIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/FinancialStatementComponentsScheduleofCarryingValuesofIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019cd9de-1707-7ad4-b508-af6993a006c0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019cd9de-1706-7179-93a1-1702fcf448cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019cd9de-1707-7ad4-b508-af6993a006c0" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019cd9de-1706-7179-93a1-1702fcf448cb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019cd9de-1706-7db4-98a7-16dccae4e47e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019cd9de-1706-7179-93a1-1702fcf448cb" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019cd9de-1706-7db4-98a7-16dccae4e47e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019cd9de-1706-7db4-98a7-16dccae4e47e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019cd9de-1706-7db4-98a7-16dccae4e47e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019cd9de-1706-7db4-98a7-16dccae4e47e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019cd9de-1706-7c40-8880-a8c748d7605e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019cd9de-1706-7db4-98a7-16dccae4e47e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019cd9de-1706-7c40-8880-a8c748d7605e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_019cd9de-1706-756d-9668-07fde0381a51" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019cd9de-1706-7c40-8880-a8c748d7605e" xlink:to="loc_us-gaap_CustomerRelationshipsMember_019cd9de-1706-756d-9668-07fde0381a51" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_019cd9de-1706-7240-86f9-b0b4e49ece7a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DevelopedTechnologyRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019cd9de-1706-7c40-8880-a8c748d7605e" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_019cd9de-1706-7240-86f9-b0b4e49ece7a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019cd9de-1707-7417-8a1f-0b91db2dc122" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019cd9de-1707-7ad4-b508-af6993a006c0" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019cd9de-1707-7417-8a1f-0b91db2dc122" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019cd9de-1707-71fa-8bed-e4b82d2ab77f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019cd9de-1707-7ad4-b508-af6993a006c0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019cd9de-1707-71fa-8bed-e4b82d2ab77f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019cd9de-1707-799d-81db-b9ad73f12af7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019cd9de-1707-7ad4-b508-af6993a006c0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019cd9de-1707-799d-81db-b9ad73f12af7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019cd9de-1707-72f2-b394-e04459d487e9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019cd9de-1707-7ad4-b508-af6993a006c0" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019cd9de-1707-72f2-b394-e04459d487e9" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/FairValueofFinancialInstrumentsScheduleofFinancialInstrumentsCarriedatFairValueDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#FairValueofFinancialInstrumentsScheduleofFinancialInstrumentsCarriedatFairValueDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/FairValueofFinancialInstrumentsScheduleofFinancialInstrumentsCarriedatFairValueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019cd9de-1707-7167-963b-ec52b62e2076" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019cd9de-1707-751d-8964-956ab912a014" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019cd9de-1707-7167-963b-ec52b62e2076" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019cd9de-1707-751d-8964-956ab912a014" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019cd9de-1707-76be-9533-a459f8780f2c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019cd9de-1707-751d-8964-956ab912a014" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019cd9de-1707-76be-9533-a459f8780f2c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019cd9de-1707-76be-9533-a459f8780f2c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019cd9de-1707-76be-9533-a459f8780f2c" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019cd9de-1707-76be-9533-a459f8780f2c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019cd9de-1707-70a1-aee6-54384c24a87e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019cd9de-1707-76be-9533-a459f8780f2c" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019cd9de-1707-70a1-aee6-54384c24a87e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019cd9de-1707-72d0-9a02-f25ca48e27b7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019cd9de-1707-70a1-aee6-54384c24a87e" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019cd9de-1707-72d0-9a02-f25ca48e27b7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019cd9de-1707-7886-829e-b21c080f8486" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019cd9de-1707-70a1-aee6-54384c24a87e" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019cd9de-1707-7886-829e-b21c080f8486" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_019cd9de-1707-748c-ae04-eff0933a4e6d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019cd9de-1707-70a1-aee6-54384c24a87e" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_019cd9de-1707-748c-ae04-eff0933a4e6d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAxis_019df8b9-5641-7ea3-9490-aefa0d42ed49" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019cd9de-1707-751d-8964-956ab912a014" xlink:to="loc_us-gaap_CashAndCashEquivalentsAxis_019df8b9-5641-7ea3-9490-aefa0d42ed49" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019df8b9-5641-7ea3-9490-aefa0d42ed49_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_019df8b9-5641-7ea3-9490-aefa0d42ed49" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019df8b9-5641-7ea3-9490-aefa0d42ed49_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019df8b9-5641-71d4-8e22-22c87ac9afa5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_019df8b9-5641-7ea3-9490-aefa0d42ed49" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019df8b9-5641-71d4-8e22-22c87ac9afa5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_019cd9de-1707-72c7-bb12-c01fbdb9c106" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MoneyMarketFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_019df8b9-5641-71d4-8e22-22c87ac9afa5" xlink:to="loc_us-gaap_MoneyMarketFundsMember_019cd9de-1707-72c7-bb12-c01fbdb9c106" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAbstract_019cd9de-1707-7ef1-b2fc-9bc329f17e1f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019cd9de-1707-7167-963b-ec52b62e2076" xlink:to="loc_us-gaap_CashAndCashEquivalentsAbstract_019cd9de-1707-7ef1-b2fc-9bc329f17e1f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019cd9de-1707-7208-a58b-1c74d57fc962" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashAndCashEquivalentsAbstract_019cd9de-1707-7ef1-b2fc-9bc329f17e1f" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019cd9de-1707-7208-a58b-1c74d57fc962" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesFairValueDisclosureAbstract_019cd9de-1707-743d-a4ec-61007c354d7c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019cd9de-1707-7167-963b-ec52b62e2076" xlink:to="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesFairValueDisclosureAbstract_019cd9de-1707-743d-a4ec-61007c354d7c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesFairValueDisclosure_019cd9de-1707-75e8-b999-9b92678a1ca6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedLiabilitiesFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesFairValueDisclosureAbstract_019cd9de-1707-743d-a4ec-61007c354d7c" xlink:to="loc_us-gaap_AccruedLiabilitiesFairValueDisclosure_019cd9de-1707-75e8-b999-9b92678a1ca6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityCurrent_019cd9de-1707-7097-a817-3870babbd4a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesFairValueDisclosureAbstract_019cd9de-1707-743d-a4ec-61007c354d7c" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityCurrent_019cd9de-1707-7097-a817-3870babbd4a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialLiabilitiesFairValueDisclosureAbstract_019cd9de-1707-7c1d-9666-f35baa0ba743" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialLiabilitiesFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019cd9de-1707-7167-963b-ec52b62e2076" xlink:to="loc_us-gaap_FinancialLiabilitiesFairValueDisclosureAbstract_019cd9de-1707-7c1d-9666-f35baa0ba743" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityStatementOfFinancialPositionExtensibleEnumeration_019d3e58-91ae-7dbc-95bd-9edcba74c7d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityStatementOfFinancialPositionExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialLiabilitiesFairValueDisclosureAbstract_019cd9de-1707-7c1d-9666-f35baa0ba743" xlink:to="loc_us-gaap_DerivativeLiabilityStatementOfFinancialPositionExtensibleEnumeration_019d3e58-91ae-7dbc-95bd-9edcba74c7d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_019cd9de-1707-79cc-8b63-501dbf167e0d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialLiabilitiesFairValueDisclosureAbstract_019cd9de-1707-7c1d-9666-f35baa0ba743" xlink:to="loc_us-gaap_DerivativeLiabilities_019cd9de-1707-79cc-8b63-501dbf167e0d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityNoncurrent_019cd9de-1707-731d-94a4-94db6649470f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialLiabilitiesFairValueDisclosureAbstract_019cd9de-1707-7c1d-9666-f35baa0ba743" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityNoncurrent_019cd9de-1707-731d-94a4-94db6649470f" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/FairValueofFinancialInstrumentsNarrativeDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#FairValueofFinancialInstrumentsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/FairValueofFinancialInstrumentsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019cd9de-1707-7103-b412-1713f75e4cfe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019cd9de-1707-73a6-b3a7-2bea5b72d3fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019cd9de-1707-7103-b412-1713f75e4cfe" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019cd9de-1707-73a6-b3a7-2bea5b72d3fa" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019cd9de-1707-7214-953c-a45354423504" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019cd9de-1707-73a6-b3a7-2bea5b72d3fa" xlink:to="loc_us-gaap_DebtInstrumentAxis_019cd9de-1707-7214-953c-a45354423504" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-7214-953c-a45354423504_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019cd9de-1707-7214-953c-a45354423504" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-7214-953c-a45354423504_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-76bf-8ce9-a4244c3e3d37" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019cd9de-1707-7214-953c-a45354423504" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-76bf-8ce9-a4244c3e3d37" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_CreditAgreementMember_019cd9de-1707-7b2a-82ca-4a116b82c68a" xlink:href="rng-20260331.xsd#rng_CreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-76bf-8ce9-a4244c3e3d37" xlink:to="loc_rng_CreditAgreementMember_019cd9de-1707-7b2a-82ca-4a116b82c68a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_SeniorNotesDueTwoThousandThirtyMember_019cd9de-1707-7702-beaa-894a03154596" xlink:href="rng-20260331.xsd#rng_SeniorNotesDueTwoThousandThirtyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-76bf-8ce9-a4244c3e3d37" xlink:to="loc_rng_SeniorNotesDueTwoThousandThirtyMember_019cd9de-1707-7702-beaa-894a03154596" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019cd9de-1707-70f9-a5c2-fa8d5e5b3c25" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019cd9de-1707-73a6-b3a7-2bea5b72d3fa" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019cd9de-1707-70f9-a5c2-fa8d5e5b3c25" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019cd9de-1707-70f9-a5c2-fa8d5e5b3c25_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019cd9de-1707-70f9-a5c2-fa8d5e5b3c25" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019cd9de-1707-70f9-a5c2-fa8d5e5b3c25_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019cd9de-1707-7188-90c1-005c213365c4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019cd9de-1707-70f9-a5c2-fa8d5e5b3c25" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019cd9de-1707-7188-90c1-005c213365c4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019cd9de-1707-7836-84aa-08199f104fb7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019cd9de-1707-7188-90c1-005c213365c4" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019cd9de-1707-7836-84aa-08199f104fb7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019cd9de-1707-7985-b5d3-2bb4f227fe08" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019cd9de-1707-73a6-b3a7-2bea5b72d3fa" xlink:to="loc_us-gaap_CreditFacilityAxis_019cd9de-1707-7985-b5d3-2bb4f227fe08" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7985-b5d3-2bb4f227fe08_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019cd9de-1707-7985-b5d3-2bb4f227fe08" xlink:to="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7985-b5d3-2bb4f227fe08_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-72b1-96b6-b1ba2bb1413b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019cd9de-1707-7985-b5d3-2bb4f227fe08" xlink:to="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-72b1-96b6-b1ba2bb1413b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019cd9de-1707-76ab-a1c0-08be665e49de" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-72b1-96b6-b1ba2bb1413b" xlink:to="loc_us-gaap_SecuredDebtMember_019cd9de-1707-76ab-a1c0-08be665e49de" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-797c-9e0b-3a56f1f0b791" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019cd9de-1707-73a6-b3a7-2bea5b72d3fa" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-797c-9e0b-3a56f1f0b791" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-797c-9e0b-3a56f1f0b791_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-797c-9e0b-3a56f1f0b791" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-797c-9e0b-3a56f1f0b791_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7332-950c-98617886f8c1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-797c-9e0b-3a56f1f0b791" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7332-950c-98617886f8c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019cd9de-1707-7a50-9caa-d1e9f125bf06" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7332-950c-98617886f8c1" xlink:to="loc_us-gaap_LineOfCreditMember_019cd9de-1707-7a50-9caa-d1e9f125bf06" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_019cd9de-1707-700a-bd49-3d9c4e4fb89c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7332-950c-98617886f8c1" xlink:to="loc_us-gaap_SeniorNotesMember_019cd9de-1707-700a-bd49-3d9c4e4fb89c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_019cd9de-1707-7ec5-8846-b8cfdda868f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019cd9de-1707-7103-b412-1713f75e4cfe" xlink:to="loc_us-gaap_LongTermDebtFairValue_019cd9de-1707-7ec5-8846-b8cfdda868f0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019cd9de-1707-7e05-a8af-e048b137657a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019cd9de-1707-7103-b412-1713f75e4cfe" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019cd9de-1707-7e05-a8af-e048b137657a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtFairValueDisclosures_019cd9de-1707-7682-ae47-2befdc3b2388" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConvertibleDebtFairValueDisclosures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019cd9de-1707-7103-b412-1713f75e4cfe" xlink:to="loc_us-gaap_ConvertibleDebtFairValueDisclosures_019cd9de-1707-7682-ae47-2befdc3b2388" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/LongTermDebtScheduleofNetCarryingAmountoftheOutstandingLongTermDebtDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#LongTermDebtScheduleofNetCarryingAmountoftheOutstandingLongTermDebtDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/LongTermDebtScheduleofNetCarryingAmountoftheOutstandingLongTermDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7a65-8978-9aa6b43f6a92" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-70c6-a2e2-341fd7329b60" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7a65-8978-9aa6b43f6a92" xlink:to="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-70c6-a2e2-341fd7329b60" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019cd9de-1707-7802-a592-cd22536e8d9e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-70c6-a2e2-341fd7329b60" xlink:to="loc_us-gaap_DebtInstrumentAxis_019cd9de-1707-7802-a592-cd22536e8d9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-7802-a592-cd22536e8d9e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019cd9de-1707-7802-a592-cd22536e8d9e" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-7802-a592-cd22536e8d9e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-722e-840d-7ade9a9fa8b6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019cd9de-1707-7802-a592-cd22536e8d9e" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-722e-840d-7ade9a9fa8b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_SeniorNotesDueTwoThousandThirtyMember_019cd9de-1707-761b-ab05-337e6153683c" xlink:href="rng-20260331.xsd#rng_SeniorNotesDueTwoThousandThirtyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-722e-840d-7ade9a9fa8b6" xlink:to="loc_rng_SeniorNotesDueTwoThousandThirtyMember_019cd9de-1707-761b-ab05-337e6153683c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_CreditAgreementMember_019cd9de-1707-7fe6-a54c-21f50b37b27f" xlink:href="rng-20260331.xsd#rng_CreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-722e-840d-7ade9a9fa8b6" xlink:to="loc_rng_CreditAgreementMember_019cd9de-1707-7fe6-a54c-21f50b37b27f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_ConvertibleSeniorNotesDue2026Member_019cd9de-1707-761e-9a4f-09c2ae0994a7" xlink:href="rng-20260331.xsd#rng_ConvertibleSeniorNotesDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-722e-840d-7ade9a9fa8b6" xlink:to="loc_rng_ConvertibleSeniorNotesDue2026Member_019cd9de-1707-761e-9a4f-09c2ae0994a7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019cd9de-1707-7b80-8bc3-a606d9efa03a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-70c6-a2e2-341fd7329b60" xlink:to="loc_us-gaap_CreditFacilityAxis_019cd9de-1707-7b80-8bc3-a606d9efa03a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7b80-8bc3-a606d9efa03a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019cd9de-1707-7b80-8bc3-a606d9efa03a" xlink:to="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7b80-8bc3-a606d9efa03a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7557-80e8-f9def683e412" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019cd9de-1707-7b80-8bc3-a606d9efa03a" xlink:to="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7557-80e8-f9def683e412" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019cd9de-1707-7ebe-8a05-fb0771a70458" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7557-80e8-f9def683e412" xlink:to="loc_us-gaap_SecuredDebtMember_019cd9de-1707-7ebe-8a05-fb0771a70458" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019cd9de-1707-7fa6-8325-b5e3f4381cd8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7557-80e8-f9def683e412" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019cd9de-1707-7fa6-8325-b5e3f4381cd8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-7b40-b3f2-37fea176c300" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-70c6-a2e2-341fd7329b60" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-7b40-b3f2-37fea176c300" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7b40-b3f2-37fea176c300_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-7b40-b3f2-37fea176c300" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7b40-b3f2-37fea176c300_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7264-b7c4-0b9df760e4cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-7b40-b3f2-37fea176c300" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7264-b7c4-0b9df760e4cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_019cd9de-1707-7823-b1ba-0a3474939784" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7264-b7c4-0b9df760e4cb" xlink:to="loc_us-gaap_SeniorNotesMember_019cd9de-1707-7823-b1ba-0a3474939784" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019cd9de-1707-7c18-9de5-e30f6284bf48" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7264-b7c4-0b9df760e4cb" xlink:to="loc_us-gaap_LineOfCreditMember_019cd9de-1707-7c18-9de5-e30f6284bf48" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtMember_019cd9de-1707-7d51-8c3a-dcc3ae46309d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConvertibleDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7264-b7c4-0b9df760e4cb" xlink:to="loc_us-gaap_ConvertibleDebtMember_019cd9de-1707-7d51-8c3a-dcc3ae46309d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_019cd9de-1707-7fff-9e98-ab601c34a2c5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7a65-8978-9aa6b43f6a92" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_019cd9de-1707-7fff-9e98-ab601c34a2c5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_019cd9de-1707-7f89-ae9a-2f5d59348a23" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7a65-8978-9aa6b43f6a92" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_019cd9de-1707-7f89-ae9a-2f5d59348a23" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_019cd9de-1707-7d6c-8f47-a1cfb5fee6a4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7a65-8978-9aa6b43f6a92" xlink:to="loc_us-gaap_LongTermDebtCurrent_019cd9de-1707-7d6c-8f47-a1cfb5fee6a4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_019cd9de-1707-7e85-875a-53827baed132" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7a65-8978-9aa6b43f6a92" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_019cd9de-1707-7e85-875a-53827baed132" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_019cd9de-1707-7c89-8476-09a61fc4501e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7a65-8978-9aa6b43f6a92" xlink:to="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_019cd9de-1707-7c89-8476-09a61fc4501e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfConvertibleDebt_019cd9de-1707-735e-9e8e-e8c346e1570e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfConvertibleDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7a65-8978-9aa6b43f6a92" xlink:to="loc_us-gaap_RepaymentsOfConvertibleDebt_019cd9de-1707-735e-9e8e-e8c346e1570e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_019cd9de-1707-7d51-9bfc-ebb7521a1d6a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentPeriodicPaymentPrincipal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7a65-8978-9aa6b43f6a92" xlink:to="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_019cd9de-1707-7d51-9bfc-ebb7521a1d6a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_DebtInstrumentQuarterlyPaymentPrincipalInterestRate_019cd9de-1707-7944-87a7-c02ce03740ad" xlink:href="rng-20260331.xsd#rng_DebtInstrumentQuarterlyPaymentPrincipalInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7a65-8978-9aa6b43f6a92" xlink:to="loc_rng_DebtInstrumentQuarterlyPaymentPrincipalInterestRate_019cd9de-1707-7944-87a7-c02ce03740ad" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019cd9de-1707-7fcf-b8e3-05451bcddd5e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7a65-8978-9aa6b43f6a92" xlink:to="loc_us-gaap_LongTermDebt_019cd9de-1707-7fcf-b8e3-05451bcddd5e" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/LongTermDebtScheduleofFutureMinimumPrincipalPaymentsoftheTermFacilityDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#LongTermDebtScheduleofFutureMinimumPrincipalPaymentsoftheTermFacilityDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/LongTermDebtScheduleofFutureMinimumPrincipalPaymentsoftheTermFacilityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7f76-bf28-0d635b2c2f3c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-7eb6-96df-76d0b23e52d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7f76-bf28-0d635b2c2f3c" xlink:to="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-7eb6-96df-76d0b23e52d5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019cd9de-1707-7e83-9c29-5ef2bf2ba3de" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-7eb6-96df-76d0b23e52d5" xlink:to="loc_us-gaap_DebtInstrumentAxis_019cd9de-1707-7e83-9c29-5ef2bf2ba3de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-7e83-9c29-5ef2bf2ba3de_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019cd9de-1707-7e83-9c29-5ef2bf2ba3de" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-7e83-9c29-5ef2bf2ba3de_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-71eb-8193-182f9ccb3aca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019cd9de-1707-7e83-9c29-5ef2bf2ba3de" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-71eb-8193-182f9ccb3aca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_CreditAgreementMember_019cd9de-1707-765f-9f1c-37c6199e4257" xlink:href="rng-20260331.xsd#rng_CreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-71eb-8193-182f9ccb3aca" xlink:to="loc_rng_CreditAgreementMember_019cd9de-1707-765f-9f1c-37c6199e4257" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_SeniorNotesDueTwoThousandThirtyMember_019cd9de-1707-778b-9e7c-5344b11f89ea" xlink:href="rng-20260331.xsd#rng_SeniorNotesDueTwoThousandThirtyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-71eb-8193-182f9ccb3aca" xlink:to="loc_rng_SeniorNotesDueTwoThousandThirtyMember_019cd9de-1707-778b-9e7c-5344b11f89ea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-7a2a-8d85-3bc7354bccd1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-7eb6-96df-76d0b23e52d5" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-7a2a-8d85-3bc7354bccd1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7a2a-8d85-3bc7354bccd1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-7a2a-8d85-3bc7354bccd1" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7a2a-8d85-3bc7354bccd1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7600-80ce-ce163858dd58" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-7a2a-8d85-3bc7354bccd1" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7600-80ce-ce163858dd58" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019cd9de-1707-70b2-b0f8-4ae28191babb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7600-80ce-ce163858dd58" xlink:to="loc_us-gaap_LineOfCreditMember_019cd9de-1707-70b2-b0f8-4ae28191babb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_019cd9de-1707-77d2-a022-f71124ac4ade" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7600-80ce-ce163858dd58" xlink:to="loc_us-gaap_SeniorNotesMember_019cd9de-1707-77d2-a022-f71124ac4ade" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019cd9de-1707-7af5-8071-261556064b79" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-7eb6-96df-76d0b23e52d5" xlink:to="loc_us-gaap_CreditFacilityAxis_019cd9de-1707-7af5-8071-261556064b79" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7af5-8071-261556064b79_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019cd9de-1707-7af5-8071-261556064b79" xlink:to="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7af5-8071-261556064b79_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7ed9-8b40-6644cbe8254b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019cd9de-1707-7af5-8071-261556064b79" xlink:to="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7ed9-8b40-6644cbe8254b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019cd9de-1707-72b9-a42a-60d884c8cd89" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7ed9-8b40-6644cbe8254b" xlink:to="loc_us-gaap_SecuredDebtMember_019cd9de-1707-72b9-a42a-60d884c8cd89" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear_019cd9de-1707-74fb-ba27-3a3b7fa4355e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7f76-bf28-0d635b2c2f3c" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear_019cd9de-1707-74fb-ba27-3a3b7fa4355e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_019cd9de-1707-7e00-b631-c7d0c2cb6dd7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7f76-bf28-0d635b2c2f3c" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_019cd9de-1707-7e00-b631-c7d0c2cb6dd7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_019cd9de-1707-71ef-a231-74979e69b7ca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7f76-bf28-0d635b2c2f3c" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_019cd9de-1707-71ef-a231-74979e69b7ca" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_019cd9de-1707-764a-a9ee-2efcc52f7ed3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7f76-bf28-0d635b2c2f3c" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_019cd9de-1707-764a-a9ee-2efcc52f7ed3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_LongTermDebtMaturityAfterYearThree_019cd9de-1707-729d-9f34-b16512a88595" xlink:href="rng-20260331.xsd#rng_LongTermDebtMaturityAfterYearThree"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7f76-bf28-0d635b2c2f3c" xlink:to="loc_rng_LongTermDebtMaturityAfterYearThree_019cd9de-1707-729d-9f34-b16512a88595" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_019cd9de-1707-760b-8995-582175d54b13" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7f76-bf28-0d635b2c2f3c" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_019cd9de-1707-760b-8995-582175d54b13" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/LongTermDebtNarrativeDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#LongTermDebtNarrativeDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/LongTermDebtNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-7034-bbcc-6d50ca489676" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-7034-bbcc-6d50ca489676" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019cd9de-1707-7a9f-8852-4a04af25678a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-7034-bbcc-6d50ca489676" xlink:to="loc_us-gaap_DebtInstrumentAxis_019cd9de-1707-7a9f-8852-4a04af25678a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-7a9f-8852-4a04af25678a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019cd9de-1707-7a9f-8852-4a04af25678a" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-7a9f-8852-4a04af25678a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-7096-a67b-ad83c73494f4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019cd9de-1707-7a9f-8852-4a04af25678a" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-7096-a67b-ad83c73494f4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_SeniorNotesDueTwoThousandThirtyMember_019cd9de-1707-75b5-b814-6a4fadff82ab" xlink:href="rng-20260331.xsd#rng_SeniorNotesDueTwoThousandThirtyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-7096-a67b-ad83c73494f4" xlink:to="loc_rng_SeniorNotesDueTwoThousandThirtyMember_019cd9de-1707-75b5-b814-6a4fadff82ab" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_ConvertibleSeniorNotesDue2026Member_019cd9de-1707-7522-9d15-464a74d3c294" xlink:href="rng-20260331.xsd#rng_ConvertibleSeniorNotesDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-7096-a67b-ad83c73494f4" xlink:to="loc_rng_ConvertibleSeniorNotesDue2026Member_019cd9de-1707-7522-9d15-464a74d3c294" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_CreditAgreementMember_019cd9de-1707-7b88-ba14-bc8a9e5b6042" xlink:href="rng-20260331.xsd#rng_CreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019cd9de-1707-7096-a67b-ad83c73494f4" xlink:to="loc_rng_CreditAgreementMember_019cd9de-1707-7b88-ba14-bc8a9e5b6042" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019cd9de-1707-7dc6-967e-e4d9a0a9f34a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-7034-bbcc-6d50ca489676" xlink:to="loc_us-gaap_CreditFacilityAxis_019cd9de-1707-7dc6-967e-e4d9a0a9f34a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7dc6-967e-e4d9a0a9f34a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019cd9de-1707-7dc6-967e-e4d9a0a9f34a" xlink:to="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7dc6-967e-e4d9a0a9f34a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7486-a2fe-743c8ef07a0e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019cd9de-1707-7dc6-967e-e4d9a0a9f34a" xlink:to="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7486-a2fe-743c8ef07a0e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019cd9de-1707-7510-a683-461fb203aac2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7486-a2fe-743c8ef07a0e" xlink:to="loc_us-gaap_SecuredDebtMember_019cd9de-1707-7510-a683-461fb203aac2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019cd9de-1707-7e59-9367-968a97505c4a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019cd9de-1707-7486-a2fe-743c8ef07a0e" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019cd9de-1707-7e59-9367-968a97505c4a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-79f3-99b3-161d9ef23f0e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-7034-bbcc-6d50ca489676" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-79f3-99b3-161d9ef23f0e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-79f3-99b3-161d9ef23f0e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-79f3-99b3-161d9ef23f0e" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-79f3-99b3-161d9ef23f0e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7b6f-b60c-b44fa8043f7f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-79f3-99b3-161d9ef23f0e" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7b6f-b60c-b44fa8043f7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_019cd9de-1707-7c47-8ef6-32228ad7dd18" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7b6f-b60c-b44fa8043f7f" xlink:to="loc_us-gaap_SeniorNotesMember_019cd9de-1707-7c47-8ef6-32228ad7dd18" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtMember_019cd9de-1707-79e0-9dc6-14fcb1715a5b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConvertibleDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7b6f-b60c-b44fa8043f7f" xlink:to="loc_us-gaap_ConvertibleDebtMember_019cd9de-1707-79e0-9dc6-14fcb1715a5b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019cd9de-1707-7440-9105-90eb60104c6e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7b6f-b60c-b44fa8043f7f" xlink:to="loc_us-gaap_LineOfCreditMember_019cd9de-1707-7440-9105-90eb60104c6e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_019cd9de-1707-760c-90d4-83177ff6d5dc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-7034-bbcc-6d50ca489676" xlink:to="loc_us-gaap_VariableRateAxis_019cd9de-1707-760c-90d4-83177ff6d5dc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019cd9de-1707-760c-90d4-83177ff6d5dc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_019cd9de-1707-760c-90d4-83177ff6d5dc" xlink:to="loc_us-gaap_VariableRateDomain_019cd9de-1707-760c-90d4-83177ff6d5dc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019cd9de-1707-7a62-bbd1-6780f30d3c2e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_019cd9de-1707-760c-90d4-83177ff6d5dc" xlink:to="loc_us-gaap_VariableRateDomain_019cd9de-1707-7a62-bbd1-6780f30d3c2e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalFundsEffectiveSwapRateMember_019cd9de-1707-7896-b03d-0dd06b33e984" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FederalFundsEffectiveSwapRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019cd9de-1707-7a62-bbd1-6780f30d3c2e" xlink:to="loc_us-gaap_FederalFundsEffectiveSwapRateMember_019cd9de-1707-7896-b03d-0dd06b33e984" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_019cd9de-1707-73b7-a05b-dd3ecc35f768" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SecuredOvernightFinancingRateSofrMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019cd9de-1707-7a62-bbd1-6780f30d3c2e" xlink:to="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_019cd9de-1707-73b7-a05b-dd3ecc35f768" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019cd9de-1707-7da8-a669-f07d09a32564" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-7034-bbcc-6d50ca489676" xlink:to="loc_srt_RangeAxis_019cd9de-1707-7da8-a669-f07d09a32564" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019cd9de-1707-7da8-a669-f07d09a32564_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019cd9de-1707-7da8-a669-f07d09a32564" xlink:to="loc_srt_RangeMember_019cd9de-1707-7da8-a669-f07d09a32564_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019cd9de-1707-7463-8ed9-b3b412e03634" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019cd9de-1707-7da8-a669-f07d09a32564" xlink:to="loc_srt_RangeMember_019cd9de-1707-7463-8ed9-b3b412e03634" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019cd9de-1707-7ff3-b27d-17a226961fc5" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019cd9de-1707-7463-8ed9-b3b412e03634" xlink:to="loc_srt_MinimumMember_019cd9de-1707-7ff3-b27d-17a226961fc5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019cd9de-1707-76f8-9bbc-7eaaf4fbc921" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019cd9de-1707-7463-8ed9-b3b412e03634" xlink:to="loc_srt_MaximumMember_019cd9de-1707-76f8-9bbc-7eaaf4fbc921" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExtinguishmentOfDebtAxis_019cd9de-1707-78e0-b3f1-d108612e4043" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ExtinguishmentOfDebtAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-7034-bbcc-6d50ca489676" xlink:to="loc_us-gaap_ExtinguishmentOfDebtAxis_019cd9de-1707-78e0-b3f1-d108612e4043" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExtinguishmentOfDebtTypeDomain_019cd9de-1707-78e0-b3f1-d108612e4043_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ExtinguishmentOfDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ExtinguishmentOfDebtAxis_019cd9de-1707-78e0-b3f1-d108612e4043" xlink:to="loc_us-gaap_ExtinguishmentOfDebtTypeDomain_019cd9de-1707-78e0-b3f1-d108612e4043_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExtinguishmentOfDebtTypeDomain_019cd9de-1707-7a2c-9801-1707511d330c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ExtinguishmentOfDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ExtinguishmentOfDebtAxis_019cd9de-1707-78e0-b3f1-d108612e4043" xlink:to="loc_us-gaap_ExtinguishmentOfDebtTypeDomain_019cd9de-1707-7a2c-9801-1707511d330c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_ProceedsFromTermLoanMember_019cd9de-1707-7082-aea1-a68b676a3a1d" xlink:href="rng-20260331.xsd#rng_ProceedsFromTermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ExtinguishmentOfDebtTypeDomain_019cd9de-1707-7a2c-9801-1707511d330c" xlink:to="loc_rng_ProceedsFromTermLoanMember_019cd9de-1707-7082-aea1-a68b676a3a1d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_CashOnHandMember_019de38b-5c3a-7cbb-9c9b-e5047211e678" xlink:href="rng-20260331.xsd#rng_CashOnHandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ExtinguishmentOfDebtTypeDomain_019cd9de-1707-7a2c-9801-1707511d330c" xlink:to="loc_rng_CashOnHandMember_019de38b-5c3a-7cbb-9c9b-e5047211e678" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019de37d-b52b-7a60-966a-c628789a47e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019cd9de-1707-7034-bbcc-6d50ca489676" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019de37d-b52b-7a60-966a-c628789a47e7" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019de37d-b52b-7a60-966a-c628789a47e7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019de37d-b52b-7a60-966a-c628789a47e7" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019de37d-b52b-7a60-966a-c628789a47e7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019de37d-b52b-7320-83a7-b1b7d87f4e03" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019de37d-b52b-7a60-966a-c628789a47e7" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019de37d-b52b-7320-83a7-b1b7d87f4e03" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019de37d-e175-762e-ab68-bfd8aea014db" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019de37d-b52b-7320-83a7-b1b7d87f4e03" xlink:to="loc_us-gaap_SubsequentEventMember_019de37d-e175-762e-ab68-bfd8aea014db" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019cd9de-1707-7d54-8b8c-a9dab17a48d1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019cd9de-1707-7d54-8b8c-a9dab17a48d1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019cd9de-1707-71d5-ad7c-6e0242d487aa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019cd9de-1707-71d5-ad7c-6e0242d487aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRepurchasedFaceAmount_019cd9de-1707-760b-9f68-c4aaa0a602ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentRepurchasedFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_DebtInstrumentRepurchasedFaceAmount_019cd9de-1707-760b-9f68-c4aaa0a602ae" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRepurchaseAmount_019cd9de-1707-725b-bb4c-b472091582ab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentRepurchaseAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_DebtInstrumentRepurchaseAmount_019cd9de-1707-725b-bb4c-b472091582ab" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_019cd9de-1707-70ba-adb1-75d037f88f8a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_019cd9de-1707-70ba-adb1-75d037f88f8a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019cd9de-1707-77cc-856a-8e4203f6bbde" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_LongTermDebt_019cd9de-1707-77cc-856a-8e4203f6bbde" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_019cd9de-1707-77db-8929-89675efd818f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_019cd9de-1707-77db-8929-89675efd818f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_019df8bc-2df1-768e-8ce8-749ec1c75917" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_019df8bc-2df1-768e-8ce8-749ec1c75917" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromDebtNetOfIssuanceCosts_019df8c6-702c-72f2-b4a3-c52a247c44c7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromDebtNetOfIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_ProceedsFromDebtNetOfIssuanceCosts_019df8c6-702c-72f2-b4a3-c52a247c44c7" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfConvertibleDebt_019cd9de-1707-7a40-b429-70c20e19cf0e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfConvertibleDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_RepaymentsOfConvertibleDebt_019cd9de-1707-7a40-b429-70c20e19cf0e" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_019d425c-fe8b-7c62-aad3-002503504398" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_LongTermDebtFairValue_019d425c-fe8b-7c62-aad3-002503504398" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_019cd9de-1707-7915-8e79-4c87ca3e70e5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_019cd9de-1707-7915-8e79-4c87ca3e70e5" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_019cd9de-1707-76bd-ad81-a1e483e6ae8b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_019cd9de-1707-76bd-ad81-a1e483e6ae8b" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019cd9de-1707-7eb1-9020-976101d3e8d6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019cd9de-1707-7eb1-9020-976101d3e8d6" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleNotesPayable_019cd9de-1707-750b-b7a8-6b4476bcfd00" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConvertibleNotesPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_ConvertibleNotesPayable_019cd9de-1707-750b-b7a8-6b4476bcfd00" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_019cd9de-1707-79f5-815d-f6819d1a03e1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_019cd9de-1707-79f5-815d-f6819d1a03e1" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts_019cd9de-1707-7b2b-aaf9-aa9511985fde" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfFinancingCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019cd9de-1707-7de2-871a-cfa26493ddbf" xlink:to="loc_us-gaap_AmortizationOfFinancingCosts_019cd9de-1707-7b2b-aaf9-aa9511985fde" xlink:type="arc" order="16"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/DerivativeInstrumentsDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#DerivativeInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/DerivativeInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019cd9de-1707-7f22-8986-a4b2aba6e221" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019cd9de-1707-708c-a1f3-9428a84ba3be" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019cd9de-1707-7f22-8986-a4b2aba6e221" xlink:to="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019cd9de-1707-708c-a1f3-9428a84ba3be" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019cd9de-1707-7138-b82d-7344bcae9387" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019cd9de-1707-708c-a1f3-9428a84ba3be" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019cd9de-1707-7138-b82d-7344bcae9387" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019cd9de-1707-7138-b82d-7344bcae9387_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019cd9de-1707-7138-b82d-7344bcae9387" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019cd9de-1707-7138-b82d-7344bcae9387_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019cd9de-1707-7293-be32-e32b1ce31ba8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019cd9de-1707-7138-b82d-7344bcae9387" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019cd9de-1707-7293-be32-e32b1ce31ba8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_019cd9de-1707-7a3a-8e9d-25355ee68df3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019cd9de-1707-7293-be32-e32b1ce31ba8" xlink:to="loc_us-gaap_InterestRateSwapMember_019cd9de-1707-7a3a-8e9d-25355ee68df3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019cd9de-1707-70c8-bf76-49eaeacaffb0" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019cd9de-1707-708c-a1f3-9428a84ba3be" xlink:to="loc_srt_RangeAxis_019cd9de-1707-70c8-bf76-49eaeacaffb0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019cd9de-1707-70c8-bf76-49eaeacaffb0_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019cd9de-1707-70c8-bf76-49eaeacaffb0" xlink:to="loc_srt_RangeMember_019cd9de-1707-70c8-bf76-49eaeacaffb0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019cd9de-1707-7add-add8-ffe8702ca224" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019cd9de-1707-70c8-bf76-49eaeacaffb0" xlink:to="loc_srt_RangeMember_019cd9de-1707-7add-add8-ffe8702ca224" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019cd9de-1707-70aa-9f36-8f623097170b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019cd9de-1707-7add-add8-ffe8702ca224" xlink:to="loc_srt_MinimumMember_019cd9de-1707-70aa-9f36-8f623097170b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019cd9de-1707-7c06-9650-a564144351c2" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019cd9de-1707-7add-add8-ffe8702ca224" xlink:to="loc_srt_MaximumMember_019cd9de-1707-7c06-9650-a564144351c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_019cd9de-1707-72b9-9be8-d9d980d9e17a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019cd9de-1707-708c-a1f3-9428a84ba3be" xlink:to="loc_us-gaap_HedgingDesignationAxis_019cd9de-1707-72b9-9be8-d9d980d9e17a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019cd9de-1707-72b9-9be8-d9d980d9e17a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_019cd9de-1707-72b9-9be8-d9d980d9e17a" xlink:to="loc_us-gaap_HedgingDesignationDomain_019cd9de-1707-72b9-9be8-d9d980d9e17a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019cd9de-1707-7a42-9794-ca34eb84d4d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_019cd9de-1707-72b9-9be8-d9d980d9e17a" xlink:to="loc_us-gaap_HedgingDesignationDomain_019cd9de-1707-7a42-9794-ca34eb84d4d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019cd9de-1707-72d0-81e7-2043f99d6822" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019cd9de-1707-7a42-9794-ca34eb84d4d5" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019cd9de-1707-72d0-81e7-2043f99d6822" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_019cd9de-1707-7265-bfa6-84757cd81211" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019cd9de-1707-7a42-9794-ca34eb84d4d5" xlink:to="loc_us-gaap_NondesignatedMember_019cd9de-1707-7265-bfa6-84757cd81211" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_019cd9de-1707-7ba1-8d7a-6fca4f472e7f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019cd9de-1707-708c-a1f3-9428a84ba3be" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_019cd9de-1707-7ba1-8d7a-6fca4f472e7f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-1707-7ba1-8d7a-6fca4f472e7f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_019cd9de-1707-7ba1-8d7a-6fca4f472e7f" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-1707-7ba1-8d7a-6fca4f472e7f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-1707-7f88-9c18-bf8ed6a2b69d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_019cd9de-1707-7ba1-8d7a-6fca4f472e7f" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-1707-7f88-9c18-bf8ed6a2b69d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseMember_019cd9de-1707-7321-a091-bb4bd3e9ae5e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-1707-7f88-9c18-bf8ed6a2b69d" xlink:to="loc_us-gaap_InterestExpenseMember_019cd9de-1707-7321-a091-bb4bd3e9ae5e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-756c-8099-ef6466272e69" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019cd9de-1707-708c-a1f3-9428a84ba3be" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-756c-8099-ef6466272e69" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-756c-8099-ef6466272e69_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-756c-8099-ef6466272e69" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-756c-8099-ef6466272e69_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7c6c-bc54-735dfad1d941" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019cd9de-1707-756c-8099-ef6466272e69" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7c6c-bc54-735dfad1d941" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_019cd9de-1707-7e0e-8aef-158386265b19" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019cd9de-1707-7c6c-bc54-735dfad1d941" xlink:to="loc_us-gaap_SeniorNotesMember_019cd9de-1707-7e0e-8aef-158386265b19" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTermOfContract_019cd9de-1707-7e88-bf64-a65732b8a3be" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019cd9de-1707-7f22-8986-a4b2aba6e221" xlink:to="loc_us-gaap_DerivativeTermOfContract_019cd9de-1707-7e88-bf64-a65732b8a3be" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFixedInterestRate_019cd9de-1707-7538-91e3-2b0fb388abd5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeFixedInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019cd9de-1707-7f22-8986-a4b2aba6e221" xlink:to="loc_us-gaap_DerivativeFixedInterestRate_019cd9de-1707-7538-91e3-2b0fb388abd5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeBasisSpreadOnVariableRate_019cd9de-1707-7d5e-8885-c280bfd1b493" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeBasisSpreadOnVariableRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019cd9de-1707-7f22-8986-a4b2aba6e221" xlink:to="loc_us-gaap_DerivativeBasisSpreadOnVariableRate_019cd9de-1707-7d5e-8885-c280bfd1b493" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_019cd9de-1707-7fcd-9a90-7ec376d428b9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019cd9de-1707-7f22-8986-a4b2aba6e221" xlink:to="loc_us-gaap_DerivativeNotionalAmount_019cd9de-1707-7fcd-9a90-7ec376d428b9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRepurchasedFaceAmount_019cd9de-1707-7a72-9494-944aa592271c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentRepurchasedFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019cd9de-1707-7f22-8986-a4b2aba6e221" xlink:to="loc_us-gaap_DebtInstrumentRepurchasedFaceAmount_019cd9de-1707-7a72-9494-944aa592271c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_019cd9de-1707-7d63-b9ad-1d9930f066a4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019cd9de-1707-7f22-8986-a4b2aba6e221" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_019cd9de-1707-7d63-b9ad-1d9930f066a4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet_019cd9de-1707-78f2-8222-58790923c53e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_019cd9de-1707-7f22-8986-a4b2aba6e221" xlink:to="loc_us-gaap_InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet_019cd9de-1707-78f2-8222-58790923c53e" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/BusinessCombinationsDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#BusinessCombinationsDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/BusinessCombinationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019cd9de-1707-72cf-8735-6a9fe8903440" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019cd9de-1707-7dd3-83f5-4502ed38a612" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019cd9de-1707-72cf-8735-6a9fe8903440" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019cd9de-1707-7dd3-83f5-4502ed38a612" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019cd9de-1707-77a9-b4ac-69fd8a665de8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019cd9de-1707-7dd3-83f5-4502ed38a612" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019cd9de-1707-77a9-b4ac-69fd8a665de8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cd9de-1707-77a9-b4ac-69fd8a665de8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019cd9de-1707-77a9-b4ac-69fd8a665de8" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cd9de-1707-77a9-b4ac-69fd8a665de8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cd9de-1707-727a-a140-a1cf71b110bb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019cd9de-1707-77a9-b4ac-69fd8a665de8" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cd9de-1707-727a-a140-a1cf71b110bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_EnterpriseCommunicationsPlatformCompanyMember_019d70b3-28d9-7200-91c4-2ef3e0a6963f" xlink:href="rng-20260331.xsd#rng_EnterpriseCommunicationsPlatformCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019cd9de-1707-727a-a140-a1cf71b110bb" xlink:to="loc_rng_EnterpriseCommunicationsPlatformCompanyMember_019d70b3-28d9-7200-91c4-2ef3e0a6963f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019e0063-c7fc-7072-ab45-3ba70a3d3e29" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019cd9de-1707-72cf-8735-6a9fe8903440" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019e0063-c7fc-7072-ab45-3ba70a3d3e29" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_019e0063-c7fc-7d08-b12b-36ac6ce7c94f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019cd9de-1707-72cf-8735-6a9fe8903440" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_019e0063-c7fc-7d08-b12b-36ac6ce7c94f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAcquiredFromAcquisition_019e0063-c7fc-7d24-9132-e339937133d7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAcquiredFromAcquisition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019cd9de-1707-72cf-8735-6a9fe8903440" xlink:to="loc_us-gaap_CashAcquiredFromAcquisition_019e0063-c7fc-7d24-9132-e339937133d7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_BusinessCombinationConsiderationTransferredIndemnityHoldback_019e022f-aab4-7504-a26f-4eacd6b8b48c" xlink:href="rng-20260331.xsd#rng_BusinessCombinationConsiderationTransferredIndemnityHoldback"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019cd9de-1707-72cf-8735-6a9fe8903440" xlink:to="loc_rng_BusinessCombinationConsiderationTransferredIndemnityHoldback_019e022f-aab4-7504-a26f-4eacd6b8b48c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_019e0063-c7fc-70b1-844b-59438b3ebed3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019cd9de-1707-72cf-8735-6a9fe8903440" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_019e0063-c7fc-70b1-844b-59438b3ebed3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_019e0231-2291-7b16-b628-f265a3d249ac" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019cd9de-1707-72cf-8735-6a9fe8903440" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_019e0231-2291-7b16-b628-f265a3d249ac" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019e0231-9693-7c86-951b-1205afb9273b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019cd9de-1707-72cf-8735-6a9fe8903440" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019e0231-9693-7c86-951b-1205afb9273b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019e0063-c7fc-7c58-9dd8-f244016e846a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019cd9de-1707-72cf-8735-6a9fe8903440" xlink:to="loc_us-gaap_Goodwill_019e0063-c7fc-7c58-9dd8-f244016e846a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_019e0232-1bd0-7dd7-b1a7-cde0e36c1329" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019cd9de-1707-72cf-8735-6a9fe8903440" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_019e0232-1bd0-7dd7-b1a7-cde0e36c1329" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019e0063-c7fc-75da-bf75-ee008e4dca17" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019cd9de-1707-72cf-8735-6a9fe8903440" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019e0063-c7fc-75da-bf75-ee008e4dca17" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/LeasesNarrativeDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#LeasesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/LeasesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionLineItems_019cd9de-1707-7c2b-bce6-4a6c83bf6b7e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionTable_019cd9de-1707-7545-9dc5-13908464a307" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019cd9de-1707-7c2b-bce6-4a6c83bf6b7e" xlink:to="loc_us-gaap_LesseeLeaseDescriptionTable_019cd9de-1707-7545-9dc5-13908464a307" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019cd9de-1707-71af-94bb-11e74885500c" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_019cd9de-1707-7545-9dc5-13908464a307" xlink:to="loc_srt_RangeAxis_019cd9de-1707-71af-94bb-11e74885500c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019cd9de-1707-71af-94bb-11e74885500c_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019cd9de-1707-71af-94bb-11e74885500c" xlink:to="loc_srt_RangeMember_019cd9de-1707-71af-94bb-11e74885500c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019cd9de-1707-7018-953a-248fee482fc3" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019cd9de-1707-71af-94bb-11e74885500c" xlink:to="loc_srt_RangeMember_019cd9de-1707-7018-953a-248fee482fc3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019cd9de-1707-7b6d-83ac-30cc6fb5bb43" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019cd9de-1707-7018-953a-248fee482fc3" xlink:to="loc_srt_MinimumMember_019cd9de-1707-7b6d-83ac-30cc6fb5bb43" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019cd9de-1707-7edf-9471-329cb7012da6" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019cd9de-1707-7018-953a-248fee482fc3" xlink:to="loc_srt_MaximumMember_019cd9de-1707-7edf-9471-329cb7012da6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseContractualTermAxis_019de3ad-3e09-730f-898b-3dab86b1ed06" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseContractualTermAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_019cd9de-1707-7545-9dc5-13908464a307" xlink:to="loc_us-gaap_LeaseContractualTermAxis_019de3ad-3e09-730f-898b-3dab86b1ed06" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseContractualTermDomain_019de3ad-3e09-730f-898b-3dab86b1ed06_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseContractualTermDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LeaseContractualTermAxis_019de3ad-3e09-730f-898b-3dab86b1ed06" xlink:to="loc_us-gaap_LeaseContractualTermDomain_019de3ad-3e09-730f-898b-3dab86b1ed06_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseContractualTermDomain_019de3ad-3e09-73e4-9dd6-1ec195e0164a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseContractualTermDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LeaseContractualTermAxis_019de3ad-3e09-730f-898b-3dab86b1ed06" xlink:to="loc_us-gaap_LeaseContractualTermDomain_019de3ad-3e09-73e4-9dd6-1ec195e0164a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_LeaseExpiring2031Member_019de3ad-6dad-79a9-b3bc-ac04226bbce2" xlink:href="rng-20260331.xsd#rng_LeaseExpiring2031Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LeaseContractualTermDomain_019de3ad-3e09-73e4-9dd6-1ec195e0164a" xlink:to="loc_rng_LeaseExpiring2031Member_019de3ad-6dad-79a9-b3bc-ac04226bbce2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseRenewalTerm_019cd9de-1707-79b1-ba11-a4b944802303" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseRenewalTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019cd9de-1707-7c2b-bce6-4a6c83bf6b7e" xlink:to="loc_us-gaap_LesseeOperatingLeaseRenewalTerm_019cd9de-1707-79b1-ba11-a4b944802303" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_019dd232-6dfe-7aad-ad19-50b09148462e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019cd9de-1707-7c2b-bce6-4a6c83bf6b7e" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_019dd232-6dfe-7aad-ad19-50b09148462e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_019de3ac-05b0-789d-a36c-41765bcf8230" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019cd9de-1707-7c2b-bce6-4a6c83bf6b7e" xlink:to="loc_us-gaap_OperatingLeaseLiability_019de3ac-05b0-789d-a36c-41765bcf8230" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetRentableArea_019dd222-55b6-7963-9d79-9cea25466dfd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetRentableArea"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019cd9de-1707-7c2b-bce6-4a6c83bf6b7e" xlink:to="loc_us-gaap_NetRentableArea_019dd222-55b6-7963-9d79-9cea25466dfd" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/StockholdersDeficitScheduleofStockRepurchaseActivityDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#StockholdersDeficitScheduleofStockRepurchaseActivityDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/StockholdersDeficitScheduleofStockRepurchaseActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019cd9de-1708-7b3a-8cf3-663c46d174bf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityClassOfTreasuryStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfTreasuryStockTable_019cd9de-1708-78a9-bd0b-436e9557bcc2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfTreasuryStockTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019cd9de-1708-7b3a-8cf3-663c46d174bf" xlink:to="loc_us-gaap_ClassOfTreasuryStockTable_019cd9de-1708-78a9-bd0b-436e9557bcc2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019cd9de-1708-7b62-8ff3-e8c838bb46c3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ClassOfTreasuryStockTable_019cd9de-1708-78a9-bd0b-436e9557bcc2" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019cd9de-1708-7b62-8ff3-e8c838bb46c3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019cd9de-1708-7b62-8ff3-e8c838bb46c3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019cd9de-1708-7b62-8ff3-e8c838bb46c3" xlink:to="loc_us-gaap_ClassOfStockDomain_019cd9de-1708-7b62-8ff3-e8c838bb46c3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019cd9de-1708-7e97-9643-b2f8bddb8459" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019cd9de-1708-7b62-8ff3-e8c838bb46c3" xlink:to="loc_us-gaap_ClassOfStockDomain_019cd9de-1708-7e97-9643-b2f8bddb8459" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019cd9de-1708-7db2-a168-d50f0913dc5c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019cd9de-1708-7e97-9643-b2f8bddb8459" xlink:to="loc_us-gaap_CommonClassAMember_019cd9de-1708-7db2-a168-d50f0913dc5c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_StockRepurchasedDuringPeriodSharesExcludingUnsettledSharesAndPriorQuarterRepurchasesSettledInCurrentQuarter_019cd9de-1708-7b32-a263-95b08c6e2625" xlink:href="rng-20260331.xsd#rng_StockRepurchasedDuringPeriodSharesExcludingUnsettledSharesAndPriorQuarterRepurchasesSettledInCurrentQuarter"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019cd9de-1708-7b3a-8cf3-663c46d174bf" xlink:to="loc_rng_StockRepurchasedDuringPeriodSharesExcludingUnsettledSharesAndPriorQuarterRepurchasesSettledInCurrentQuarter_019cd9de-1708-7b32-a263-95b08c6e2625" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_StockRepurchasedDuringPeriodValueGross_019cd9de-1708-7da9-bb58-c74cc9cf93a2" xlink:href="rng-20260331.xsd#rng_StockRepurchasedDuringPeriodValueGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019cd9de-1708-7b3a-8cf3-663c46d174bf" xlink:to="loc_rng_StockRepurchasedDuringPeriodValueGross_019cd9de-1708-7da9-bb58-c74cc9cf93a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_StockRepurchasedDuringPeriodValueExciseTaxWithholdingsAndBrokerCommissions_019cd9de-1708-7556-b3aa-766f0b86f7c6" xlink:href="rng-20260331.xsd#rng_StockRepurchasedDuringPeriodValueExciseTaxWithholdingsAndBrokerCommissions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019cd9de-1708-7b3a-8cf3-663c46d174bf" xlink:to="loc_rng_StockRepurchasedDuringPeriodValueExciseTaxWithholdingsAndBrokerCommissions_019cd9de-1708-7556-b3aa-766f0b86f7c6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_019cd9de-1708-732a-99b5-29647daefd44" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockRepurchasedDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019cd9de-1708-7b3a-8cf3-663c46d174bf" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_019cd9de-1708-732a-99b5-29647daefd44" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/StockholdersDeficitNarrativeDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#StockholdersDeficitNarrativeDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/StockholdersDeficitNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_019dfee1-f05f-7d42-9042-1623302fcc13" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_019dfee1-f05f-7bbc-b83b-1af0b2716729" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_019dfee1-f05f-7d42-9042-1623302fcc13" xlink:to="loc_us-gaap_SubsequentEventTable_019dfee1-f05f-7bbc-b83b-1af0b2716729" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019dfee1-f05f-7274-9210-cc8d12f1fa9e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019dfee1-f05f-7bbc-b83b-1af0b2716729" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019dfee1-f05f-7274-9210-cc8d12f1fa9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019dfee1-f05f-7274-9210-cc8d12f1fa9e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019dfee1-f05f-7274-9210-cc8d12f1fa9e" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019dfee1-f05f-7274-9210-cc8d12f1fa9e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019dfee1-f05f-7bbb-b0d2-93f129d3d7e9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019dfee1-f05f-7274-9210-cc8d12f1fa9e" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019dfee1-f05f-7bbb-b0d2-93f129d3d7e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019dfee1-f05f-7aa2-8993-0b0a33bf94fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019dfee1-f05f-7bbb-b0d2-93f129d3d7e9" xlink:to="loc_us-gaap_SubsequentEventMember_019dfee1-f05f-7aa2-8993-0b0a33bf94fa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_019cd9de-1708-71b5-984a-c399fdb8775d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019dfee1-f05f-7d42-9042-1623302fcc13" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_019cd9de-1708-71b5-984a-c399fdb8775d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_ShareRepurchaseProgramRemainingAuthorizedExcludingPriorRepurchasesAmount_019de3b4-a16d-730b-8318-48d1e6b94daf" xlink:href="rng-20260331.xsd#rng_ShareRepurchaseProgramRemainingAuthorizedExcludingPriorRepurchasesAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019dfee1-f05f-7d42-9042-1623302fcc13" xlink:to="loc_rng_ShareRepurchaseProgramRemainingAuthorizedExcludingPriorRepurchasesAmount_019de3b4-a16d-730b-8318-48d1e6b94daf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_019dfedb-b307-7017-8eed-1f0db0ed57d6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockDividendsPerShareDeclared"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019dfee1-f05f-7d42-9042-1623302fcc13" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_019dfedb-b307-7017-8eed-1f0db0ed57d6" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/StockholdersDeficitScheduleofShareRepurchasedandSettledDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#StockholdersDeficitScheduleofShareRepurchasedandSettledDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/StockholdersDeficitScheduleofShareRepurchasedandSettledDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019cd9de-1708-7f15-8e70-80498557963f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityClassOfTreasuryStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfTreasuryStockTable_019cd9de-1708-7b4c-b74c-6ada7769b770" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfTreasuryStockTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019cd9de-1708-7f15-8e70-80498557963f" xlink:to="loc_us-gaap_ClassOfTreasuryStockTable_019cd9de-1708-7b4c-b74c-6ada7769b770" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019cd9de-1708-7c57-88f1-4571a1f67d17" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ClassOfTreasuryStockTable_019cd9de-1708-7b4c-b74c-6ada7769b770" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019cd9de-1708-7c57-88f1-4571a1f67d17" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019cd9de-1708-7c57-88f1-4571a1f67d17_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019cd9de-1708-7c57-88f1-4571a1f67d17" xlink:to="loc_us-gaap_ClassOfStockDomain_019cd9de-1708-7c57-88f1-4571a1f67d17_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019cd9de-1708-7a42-874d-b76d5204abc4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019cd9de-1708-7c57-88f1-4571a1f67d17" xlink:to="loc_us-gaap_ClassOfStockDomain_019cd9de-1708-7a42-874d-b76d5204abc4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019cd9de-1708-781d-8bde-3b7a523150ea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019cd9de-1708-7a42-874d-b76d5204abc4" xlink:to="loc_us-gaap_CommonClassAMember_019cd9de-1708-781d-8bde-3b7a523150ea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_StockRepurchasedDuringPeriodSharesExcludingUnsettledSharesAndPriorQuarterRepurchasesSettledInCurrentQuarter_019cd9de-1708-7a84-9d27-9d5bfeaf6248" xlink:href="rng-20260331.xsd#rng_StockRepurchasedDuringPeriodSharesExcludingUnsettledSharesAndPriorQuarterRepurchasesSettledInCurrentQuarter"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019cd9de-1708-7f15-8e70-80498557963f" xlink:to="loc_rng_StockRepurchasedDuringPeriodSharesExcludingUnsettledSharesAndPriorQuarterRepurchasesSettledInCurrentQuarter_019cd9de-1708-7a84-9d27-9d5bfeaf6248" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_StockRepurchasedDuringPeriodSharesUnsettled_019cd9de-1708-708f-b9b0-0f601f25d7fa" xlink:href="rng-20260331.xsd#rng_StockRepurchasedDuringPeriodSharesUnsettled"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019cd9de-1708-7f15-8e70-80498557963f" xlink:to="loc_rng_StockRepurchasedDuringPeriodSharesUnsettled_019cd9de-1708-708f-b9b0-0f601f25d7fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_StockRepurchasedInPriorPeriodSharesSettledInCurrentYear_019cd9de-1708-7b52-9189-f28fb06ea030" xlink:href="rng-20260331.xsd#rng_StockRepurchasedInPriorPeriodSharesSettledInCurrentYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019cd9de-1708-7f15-8e70-80498557963f" xlink:to="loc_rng_StockRepurchasedInPriorPeriodSharesSettledInCurrentYear_019cd9de-1708-7b52-9189-f28fb06ea030" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_019cd9de-1708-7d25-8316-c66eeea08cc7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockRepurchasedDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019cd9de-1708-7f15-8e70-80498557963f" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_019cd9de-1708-7d25-8316-c66eeea08cc7" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/ShareBasedCompensationScheduleofShareBasedCompensationExpenseRecognizedtoStatementsofOperationsDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#ShareBasedCompensationScheduleofShareBasedCompensationExpenseRecognizedtoStatementsofOperationsDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/ShareBasedCompensationScheduleofShareBasedCompensationExpenseRecognizedtoStatementsofOperationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019cd9de-17b6-7625-a01a-60e9a2bff1d1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019cd9de-17b6-7ee0-86e9-f9077359dd77" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019cd9de-17b6-7625-a01a-60e9a2bff1d1" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019cd9de-17b6-7ee0-86e9-f9077359dd77" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_019cd9de-17b6-7d68-b652-e9e9c0b8c91e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019cd9de-17b6-7ee0-86e9-f9077359dd77" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_019cd9de-17b6-7d68-b652-e9e9c0b8c91e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-17b6-7d68-b652-e9e9c0b8c91e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_019cd9de-17b6-7d68-b652-e9e9c0b8c91e" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-17b6-7d68-b652-e9e9c0b8c91e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-17b6-7247-b1e2-923d4a51535c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_019cd9de-17b6-7d68-b652-e9e9c0b8c91e" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-17b6-7247-b1e2-923d4a51535c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_019cd9de-17b6-7451-a8d4-4140c9192be6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-17b6-7247-b1e2-923d4a51535c" xlink:to="loc_us-gaap_CostOfSalesMember_019cd9de-17b6-7451-a8d4-4140c9192be6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseMember_019cd9de-17b6-77c8-a850-3b80ebebd8d4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-17b6-7247-b1e2-923d4a51535c" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseMember_019cd9de-17b6-77c8-a850-3b80ebebd8d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpenseMember_019cd9de-17b6-7f88-a644-3b6e37f34b62" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingAndMarketingExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-17b6-7247-b1e2-923d4a51535c" xlink:to="loc_us-gaap_SellingAndMarketingExpenseMember_019cd9de-17b6-7f88-a644-3b6e37f34b62" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_019cd9de-17b6-7250-bcdd-55a2b1ffa563" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-17b6-7247-b1e2-923d4a51535c" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_019cd9de-17b6-7250-bcdd-55a2b1ffa563" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019cd9de-17b6-7b18-afaf-ba251ad5a273" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019cd9de-17b6-7625-a01a-60e9a2bff1d1" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019cd9de-17b6-7b18-afaf-ba251ad5a273" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/ShareBasedCompensationScheduleofShareBasedCompensationExpensebyAwardTypeDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#ShareBasedCompensationScheduleofShareBasedCompensationExpensebyAwardTypeDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/ShareBasedCompensationScheduleofShareBasedCompensationExpensebyAwardTypeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-7df6-ba6d-eb2506dc5946" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019cd9de-17b6-7275-ad02-ec801db7d15c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-7df6-ba6d-eb2506dc5946" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019cd9de-17b6-7275-ad02-ec801db7d15c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019cd9de-17b6-7b34-b84f-676cb4199f50" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019cd9de-17b6-7275-ad02-ec801db7d15c" xlink:to="loc_us-gaap_AwardTypeAxis_019cd9de-17b6-7b34-b84f-676cb4199f50" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-7b34-b84f-676cb4199f50_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019cd9de-17b6-7b34-b84f-676cb4199f50" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-7b34-b84f-676cb4199f50_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-7d7f-9815-0e54658b563d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019cd9de-17b6-7b34-b84f-676cb4199f50" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-7d7f-9815-0e54658b563d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockMember_019cd9de-17b6-7c5a-821b-95604d20ccc2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-7d7f-9815-0e54658b563d" xlink:to="loc_us-gaap_EmployeeStockMember_019cd9de-17b6-7c5a-821b-95604d20ccc2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_019cd9de-17b6-7a23-b031-89b8b51f0bbd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-7d7f-9815-0e54658b563d" xlink:to="loc_us-gaap_PerformanceSharesMember_019cd9de-17b6-7a23-b031-89b8b51f0bbd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019cd9de-17b6-762e-98df-9e0a27e5994a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-7d7f-9815-0e54658b563d" xlink:to="loc_us-gaap_RestrictedStockMember_019cd9de-17b6-762e-98df-9e0a27e5994a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019cd9de-17b6-7142-847f-1af0c8e0f9d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-7df6-ba6d-eb2506dc5946" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019cd9de-17b6-7142-847f-1af0c8e0f9d5" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/ShareBasedCompensationNarrativeDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#ShareBasedCompensationNarrativeDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/ShareBasedCompensationNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-744d-bec8-6e4910a98155" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019cd9de-17b6-70b9-a641-9e9babee9f3b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-744d-bec8-6e4910a98155" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019cd9de-17b6-70b9-a641-9e9babee9f3b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_019cd9de-17b6-7134-8944-63642f6defbd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019cd9de-17b6-70b9-a641-9e9babee9f3b" xlink:to="loc_us-gaap_PlanNameAxis_019cd9de-17b6-7134-8944-63642f6defbd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019cd9de-17b6-7134-8944-63642f6defbd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_019cd9de-17b6-7134-8944-63642f6defbd" xlink:to="loc_us-gaap_PlanNameDomain_019cd9de-17b6-7134-8944-63642f6defbd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019cd9de-17b6-7e80-9fd7-13094533dea3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_019cd9de-17b6-7134-8944-63642f6defbd" xlink:to="loc_us-gaap_PlanNameDomain_019cd9de-17b6-7e80-9fd7-13094533dea3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_TwoThousandAndThirteenEquityAndIncentivePlanMember_019cd9de-17b6-7681-ba93-c03132501f4e" xlink:href="rng-20260331.xsd#rng_TwoThousandAndThirteenEquityAndIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019cd9de-17b6-7e80-9fd7-13094533dea3" xlink:to="loc_rng_TwoThousandAndThirteenEquityAndIncentivePlanMember_019cd9de-17b6-7681-ba93-c03132501f4e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_KeyEmployeeEquityBonusPlanMember_019cd9de-17b6-750a-9760-0a9c9c8658db" xlink:href="rng-20260331.xsd#rng_KeyEmployeeEquityBonusPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019cd9de-17b6-7e80-9fd7-13094533dea3" xlink:to="loc_rng_KeyEmployeeEquityBonusPlanMember_019cd9de-17b6-750a-9760-0a9c9c8658db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019cd9de-17b6-792f-afd9-e6b74e0fe473" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019cd9de-17b6-70b9-a641-9e9babee9f3b" xlink:to="loc_us-gaap_AwardTypeAxis_019cd9de-17b6-792f-afd9-e6b74e0fe473" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-792f-afd9-e6b74e0fe473_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019cd9de-17b6-792f-afd9-e6b74e0fe473" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-792f-afd9-e6b74e0fe473_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-7e61-a8c4-358af890e948" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019cd9de-17b6-792f-afd9-e6b74e0fe473" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-7e61-a8c4-358af890e948" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockMember_019cd9de-17b6-77b4-854b-d8fb202a6d76" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-7e61-a8c4-358af890e948" xlink:to="loc_us-gaap_EmployeeStockMember_019cd9de-17b6-77b4-854b-d8fb202a6d76" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019cd9de-17b6-787d-92ed-fb678a062c5b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-7e61-a8c4-358af890e948" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019cd9de-17b6-787d-92ed-fb678a062c5b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_019cd9de-17b6-762b-b151-bc5424176fe9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-7e61-a8c4-358af890e948" xlink:to="loc_us-gaap_PerformanceSharesMember_019cd9de-17b6-762b-b151-bc5424176fe9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019cd9de-17b6-7de3-bc41-6501d29304fa" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019cd9de-17b6-70b9-a641-9e9babee9f3b" xlink:to="loc_srt_RangeAxis_019cd9de-17b6-7de3-bc41-6501d29304fa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019cd9de-17b6-7de3-bc41-6501d29304fa_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019cd9de-17b6-7de3-bc41-6501d29304fa" xlink:to="loc_srt_RangeMember_019cd9de-17b6-7de3-bc41-6501d29304fa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019cd9de-17b6-7b0e-872f-aa7e5a620338" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019cd9de-17b6-7de3-bc41-6501d29304fa" xlink:to="loc_srt_RangeMember_019cd9de-17b6-7b0e-872f-aa7e5a620338" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019cd9de-17b6-7f74-b236-ab032198efbe" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019cd9de-17b6-7b0e-872f-aa7e5a620338" xlink:to="loc_srt_MinimumMember_019cd9de-17b6-7f74-b236-ab032198efbe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019cd9de-17b6-726b-84d8-90657b85f529" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019cd9de-17b6-7b0e-872f-aa7e5a620338" xlink:to="loc_srt_MaximumMember_019cd9de-17b6-726b-84d8-90657b85f529" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_019cd9de-17b6-7f71-95c4-6f72786ed8ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-744d-bec8-6e4910a98155" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_019cd9de-17b6-7f71-95c4-6f72786ed8ff" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_019cd9de-17b6-7497-bd81-b4a1326a2c37" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-744d-bec8-6e4910a98155" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_019cd9de-17b6-7497-bd81-b4a1326a2c37" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019cd9de-17b6-7193-91a0-4f67c2f3cefe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-744d-bec8-6e4910a98155" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019cd9de-17b6-7193-91a0-4f67c2f3cefe" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019cd9de-17b6-7300-9a9f-55ce2d1db96d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-744d-bec8-6e4910a98155" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019cd9de-17b6-7300-9a9f-55ce2d1db96d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_019cd9de-17b6-75b2-89d1-4509ab1c9428" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-744d-bec8-6e4910a98155" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_019cd9de-17b6-75b2-89d1-4509ab1c9428" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_019cd9de-17b6-7c19-872b-01fbf894cb35" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-744d-bec8-6e4910a98155" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_019cd9de-17b6-7c19-872b-01fbf894cb35" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019cd9de-17b6-7836-a6de-f6e4249f26dd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-744d-bec8-6e4910a98155" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019cd9de-17b6-7836-a6de-f6e4249f26dd" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_ShareBasedCompensationRequisiteServicePeriodRecognition_019cd9de-17b6-7f5b-85c4-ef67879f2f2b" xlink:href="rng-20260331.xsd#rng_ShareBasedCompensationRequisiteServicePeriodRecognition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-744d-bec8-6e4910a98155" xlink:to="loc_rng_ShareBasedCompensationRequisiteServicePeriodRecognition_019cd9de-17b6-7f5b-85c4-ef67879f2f2b" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/ShareBasedCompensationScheduleofRSUsActivityDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#ShareBasedCompensationScheduleofRSUsActivityDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/ShareBasedCompensationScheduleofRSUsActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-73bb-a215-5ba559044f0a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019cd9de-17b6-7f09-b278-4e483ddb73a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-73bb-a215-5ba559044f0a" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019cd9de-17b6-7f09-b278-4e483ddb73a8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019cd9de-17b6-7411-804a-11d2ca1c05aa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019cd9de-17b6-7f09-b278-4e483ddb73a8" xlink:to="loc_us-gaap_AwardTypeAxis_019cd9de-17b6-7411-804a-11d2ca1c05aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-7411-804a-11d2ca1c05aa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019cd9de-17b6-7411-804a-11d2ca1c05aa" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-7411-804a-11d2ca1c05aa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-71ee-ac97-3bc828b6f902" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019cd9de-17b6-7411-804a-11d2ca1c05aa" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-71ee-ac97-3bc828b6f902" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_RestrictedStockAndPerformanceSharesMember_019cd9de-17b6-7bfb-bcdf-8be4a40af217" xlink:href="rng-20260331.xsd#rng_RestrictedStockAndPerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019cd9de-17b6-71ee-ac97-3bc828b6f902" xlink:to="loc_rng_RestrictedStockAndPerformanceSharesMember_019cd9de-17b6-7bfb-bcdf-8be4a40af217" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019cd9de-17b6-7513-9017-9995d1387d6e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-73bb-a215-5ba559044f0a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019cd9de-17b6-7513-9017-9995d1387d6e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019cd9de-17b6-7b11-a2dc-ae5e29c33ec9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019cd9de-17b6-7513-9017-9995d1387d6e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019cd9de-17b6-7b11-a2dc-ae5e29c33ec9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019cd9de-17b6-7002-a528-6421d09328b1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019cd9de-17b6-7513-9017-9995d1387d6e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019cd9de-17b6-7002-a528-6421d09328b1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019cd9de-17b6-7b05-91ef-65295e2c12f9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019cd9de-17b6-7513-9017-9995d1387d6e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019cd9de-17b6-7b05-91ef-65295e2c12f9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019cd9de-17b6-77e1-b1ce-7390c5bb309b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019cd9de-17b6-7513-9017-9995d1387d6e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019cd9de-17b6-77e1-b1ce-7390c5bb309b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019cd9de-17b6-7dce-8e8e-d5f5857a8b50" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019cd9de-17b6-76de-9451-0cd78c623d6c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-73bb-a215-5ba559044f0a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019cd9de-17b6-76de-9451-0cd78c623d6c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019cd9de-17b6-7617-98c5-a39938a89cba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019cd9de-17b6-76de-9451-0cd78c623d6c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019cd9de-17b6-7617-98c5-a39938a89cba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019cd9de-17b6-7dea-90c0-98c24363dfdd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019cd9de-17b6-76de-9451-0cd78c623d6c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019cd9de-17b6-7dea-90c0-98c24363dfdd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019cd9de-17b6-7e83-8754-c45022344757" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019cd9de-17b6-76de-9451-0cd78c623d6c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019cd9de-17b6-7e83-8754-c45022344757" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019cd9de-17b6-717a-999f-7a903cfd4fa3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019cd9de-17b6-76de-9451-0cd78c623d6c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019cd9de-17b6-717a-999f-7a903cfd4fa3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019cd9de-17b6-7697-8230-3e19d250bded" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueAbstract_019cd9de-17b6-76b5-8cf4-4c237e38cea5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019cd9de-17b6-73bb-a215-5ba559044f0a" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueAbstract_019cd9de-17b6-76b5-8cf4-4c237e38cea5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstanding_019cd9de-17b6-7d2d-9445-35854910e4c9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueAbstract_019cd9de-17b6-76b5-8cf4-4c237e38cea5" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstanding_019cd9de-17b6-7d2d-9445-35854910e4c9" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/BasicandDilutedNetIncomeLossPerShareScheduleofPotentialSharesofCommonStockExcludedfromDilutedWeightedAverageCommonSharesOutstandingDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#BasicandDilutedNetIncomeLossPerShareScheduleofPotentialSharesofCommonStockExcludedfromDilutedWeightedAverageCommonSharesOutstandingDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/BasicandDilutedNetIncomeLossPerShareScheduleofPotentialSharesofCommonStockExcludedfromDilutedWeightedAverageCommonSharesOutstandingDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019cd9de-17b6-7847-9cb6-0ffd30f1b699" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019cd9de-17b6-70e6-91a2-41a3869e5017" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019cd9de-17b6-7847-9cb6-0ffd30f1b699" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019cd9de-17b6-70e6-91a2-41a3869e5017" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019cd9de-17b6-77ce-9512-89ca2dbde6b8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019cd9de-17b6-70e6-91a2-41a3869e5017" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019cd9de-17b6-77ce-9512-89ca2dbde6b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019cd9de-17b6-77ce-9512-89ca2dbde6b8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019cd9de-17b6-77ce-9512-89ca2dbde6b8" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019cd9de-17b6-77ce-9512-89ca2dbde6b8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019cd9de-17b6-763f-952e-fc4dad09b4a7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019cd9de-17b6-77ce-9512-89ca2dbde6b8" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019cd9de-17b6-763f-952e-fc4dad09b4a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockCompensationPlanMember_019cd9de-17b6-7ce9-8473-b3048139827c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockCompensationPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019cd9de-17b6-763f-952e-fc4dad09b4a7" xlink:to="loc_us-gaap_StockCompensationPlanMember_019cd9de-17b6-7ce9-8473-b3048139827c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_SeriesAConvertiblePreferredStockMember_019cd9de-17b6-7c0c-859d-5191451a57a8" xlink:href="rng-20260331.xsd#rng_SeriesAConvertiblePreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019cd9de-17b6-763f-952e-fc4dad09b4a7" xlink:to="loc_rng_SeriesAConvertiblePreferredStockMember_019cd9de-17b6-7c0c-859d-5191451a57a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019cd9de-17b6-705e-9804-f06ab657ca14" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019cd9de-17b6-7847-9cb6-0ffd30f1b699" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019cd9de-17b6-705e-9804-f06ab657ca14" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/RestructuringActivitiesScheduleofRestructuringCostsDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#RestructuringActivitiesScheduleofRestructuringCostsDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/RestructuringActivitiesScheduleofRestructuringCostsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_019cd9de-17b6-71a6-9284-9f8a891ff805" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019cd9de-17b6-7107-8611-2b5dbcd0e32c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019cd9de-17b6-71a6-9284-9f8a891ff805" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019cd9de-17b6-7107-8611-2b5dbcd0e32c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_019cd9de-17b6-7dea-abbd-16fe12186800" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019cd9de-17b6-7107-8611-2b5dbcd0e32c" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_019cd9de-17b6-7dea-abbd-16fe12186800" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-17b6-7dea-abbd-16fe12186800_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_019cd9de-17b6-7dea-abbd-16fe12186800" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-17b6-7dea-abbd-16fe12186800_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-17b6-7650-8516-004d18d948e1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_019cd9de-17b6-7dea-abbd-16fe12186800" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-17b6-7650-8516-004d18d948e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_019cd9de-17b6-7b34-a973-051e44413958" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-17b6-7650-8516-004d18d948e1" xlink:to="loc_us-gaap_CostOfSalesMember_019cd9de-17b6-7b34-a973-051e44413958" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseMember_019cd9de-17b6-712a-8321-83982a6ca693" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-17b6-7650-8516-004d18d948e1" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseMember_019cd9de-17b6-712a-8321-83982a6ca693" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpenseMember_019cd9de-17b6-706c-9c44-1de6716755f6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingAndMarketingExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-17b6-7650-8516-004d18d948e1" xlink:to="loc_us-gaap_SellingAndMarketingExpenseMember_019cd9de-17b6-706c-9c44-1de6716755f6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_019cd9de-17b6-7b07-9283-7823084110ce" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_019cd9de-17b6-7650-8516-004d18d948e1" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_019cd9de-17b6-7b07-9283-7823084110ce" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCosts_019cd9de-17b6-7c85-a23a-e58cc6687b3b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestructuringCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019cd9de-17b6-71a6-9284-9f8a891ff805" xlink:to="loc_us-gaap_RestructuringCosts_019cd9de-17b6-7c85-a23a-e58cc6687b3b" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/SegmentInformationNarrativeDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#SegmentInformationNarrativeDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/SegmentInformationNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019cd9de-17b6-72d0-9e5b-8304718c062f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019cd9de-17b6-7409-b5c0-d3d4a824ad85" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019cd9de-17b6-72d0-9e5b-8304718c062f" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019cd9de-17b6-7409-b5c0-d3d4a824ad85" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019cd9de-17b6-73b8-a68e-192f12e0550f" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019cd9de-17b6-7409-b5c0-d3d4a824ad85" xlink:to="loc_srt_StatementGeographicalAxis_019cd9de-17b6-73b8-a68e-192f12e0550f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019cd9de-17b6-73b8-a68e-192f12e0550f_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019cd9de-17b6-73b8-a68e-192f12e0550f" xlink:to="loc_srt_SegmentGeographicalDomain_019cd9de-17b6-73b8-a68e-192f12e0550f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019cd9de-17b6-7825-9d87-12ee24f07260" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019cd9de-17b6-73b8-a68e-192f12e0550f" xlink:to="loc_srt_SegmentGeographicalDomain_019cd9de-17b6-7825-9d87-12ee24f07260" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019cd9de-17b6-7f33-a4e7-f7de8c5900ce" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019cd9de-17b6-7825-9d87-12ee24f07260" xlink:to="loc_country_US_019cd9de-17b6-7f33-a4e7-f7de8c5900ce" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019cd9de-17b6-7e07-828a-e778bca786e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019cd9de-17b6-7409-b5c0-d3d4a824ad85" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019cd9de-17b6-7e07-828a-e778bca786e7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-17b6-7e07-828a-e778bca786e7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019cd9de-17b6-7e07-828a-e778bca786e7" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-17b6-7e07-828a-e778bca786e7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-17b6-7aa8-a682-dfe84416d82a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_019cd9de-17b6-7e07-828a-e778bca786e7" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-17b6-7aa8-a682-dfe84416d82a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentMember_019cd9de-17b6-7cc7-ac9a-0e8945c9dbc8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_019cd9de-17b6-7aa8-a682-dfe84416d82a" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentMember_019cd9de-17b6-7cc7-ac9a-0e8945c9dbc8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_019cd9de-17b6-7e4e-9995-1d82d653bc54" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019cd9de-17b6-7409-b5c0-d3d4a824ad85" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_019cd9de-17b6-7e4e-9995-1d82d653bc54" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-17b6-7e4e-9995-1d82d653bc54_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019cd9de-17b6-7e4e-9995-1d82d653bc54" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-17b6-7e4e-9995-1d82d653bc54_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-17b6-781e-9441-7edbe961460c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_019cd9de-17b6-7e4e-9995-1d82d653bc54" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-17b6-781e-9441-7edbe961460c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicConcentrationRiskMember_019cd9de-17b6-7145-a111-577e38a3b1cf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeographicConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_019cd9de-17b6-781e-9441-7edbe961460c" xlink:to="loc_us-gaap_GeographicConcentrationRiskMember_019cd9de-17b6-7145-a111-577e38a3b1cf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_019cd9de-17b6-70af-8db0-cb32870e9559" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019cd9de-17b6-72d0-9e5b-8304718c062f" xlink:to="loc_us-gaap_NumberOfReportableSegments_019cd9de-17b6-70af-8db0-cb32870e9559" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfOperatingSegments_019cd9de-17b6-7530-8cd9-afed7eedac66" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NumberOfOperatingSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019cd9de-17b6-72d0-9e5b-8304718c062f" xlink:to="loc_us-gaap_NumberOfOperatingSegments_019cd9de-17b6-7530-8cd9-afed7eedac66" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_019cd9de-17b6-71ee-8a0f-b2338a5f1986" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019cd9de-17b6-72d0-9e5b-8304718c062f" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_019cd9de-17b6-71ee-8a0f-b2338a5f1986" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://ringcentral.com/role/SegmentInformationScheduleofReconciliationofNetIncomeDetails" xlink:type="simple" xlink:href="rng-20260331.xsd#SegmentInformationScheduleofReconciliationofNetIncomeDetails"/>
  <link:definitionLink xlink:role="http://ringcentral.com/role/SegmentInformationScheduleofReconciliationofNetIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019cd9de-17b6-7f04-ad7f-71f8c0b96b8c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019cd9de-17b6-793f-bcb3-03be4c78754a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019cd9de-17b6-7f04-ad7f-71f8c0b96b8c" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019cd9de-17b6-793f-bcb3-03be4c78754a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019cd9de-17b6-73cf-b5ce-ede4a2ad528d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019cd9de-17b6-793f-bcb3-03be4c78754a" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019cd9de-17b6-73cf-b5ce-ede4a2ad528d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019cd9de-17b6-73cf-b5ce-ede4a2ad528d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019cd9de-17b6-73cf-b5ce-ede4a2ad528d" xlink:to="loc_us-gaap_SegmentDomain_019cd9de-17b6-73cf-b5ce-ede4a2ad528d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019cd9de-17b6-7a89-b49d-010a4d10f77f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019cd9de-17b6-73cf-b5ce-ede4a2ad528d" xlink:to="loc_us-gaap_SegmentDomain_019cd9de-17b6-7a89-b49d-010a4d10f77f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_ReportableSegmentMember_019cd9de-17b6-772f-ae93-f3cd0b87fd0e" xlink:href="rng-20260331.xsd#rng_ReportableSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019cd9de-17b6-7a89-b49d-010a4d10f77f" xlink:to="loc_rng_ReportableSegmentMember_019cd9de-17b6-772f-ae93-f3cd0b87fd0e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019cd9de-17b6-7b9b-b73a-3ab100109d0a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019cd9de-17b6-7f04-ad7f-71f8c0b96b8c" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019cd9de-17b6-7b9b-b73a-3ab100109d0a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationOperatingIncomeLossAbstract_019cd9de-17b6-761e-a4da-01a9de724d99" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationOperatingIncomeLossAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019cd9de-17b6-7f04-ad7f-71f8c0b96b8c" xlink:to="loc_us-gaap_SegmentReportingInformationOperatingIncomeLossAbstract_019cd9de-17b6-761e-a4da-01a9de724d99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019cd9de-17b6-7c84-a36b-3dc5a518bdd4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationOperatingIncomeLossAbstract_019cd9de-17b6-761e-a4da-01a9de724d99" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019cd9de-17b6-7c84-a36b-3dc5a518bdd4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_019cd9de-17b6-7cb2-931a-7fe2f5de65f3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationOperatingIncomeLossAbstract_019cd9de-17b6-761e-a4da-01a9de724d99" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_019cd9de-17b6-7cb2-931a-7fe2f5de65f3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingOtherItemAmount_019cd9de-17b6-76a5-bf71-7976df887b37" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingOtherItemAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationOperatingIncomeLossAbstract_019cd9de-17b6-761e-a4da-01a9de724d99" xlink:to="loc_us-gaap_SegmentReportingOtherItemAmount_019cd9de-17b6-76a5-bf71-7976df887b37" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019cd9de-17b6-7151-bdcb-7861ba1cf431" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019cd9de-17b6-7f04-ad7f-71f8c0b96b8c" xlink:to="loc_us-gaap_OperatingIncomeLoss_019cd9de-17b6-7151-bdcb-7861ba1cf431" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_OperatingRevenueMarginPercentage_019cd9de-17b6-7c4f-8610-7b797a0d9e00" xlink:href="rng-20260331.xsd#rng_OperatingRevenueMarginPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019cd9de-17b6-7f04-ad7f-71f8c0b96b8c" xlink:to="loc_rng_OperatingRevenueMarginPercentage_019cd9de-17b6-7c4f-8610-7b797a0d9e00" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_019cd9de-17b6-756e-a334-f6ca61edc155" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonoperatingIncomeExpenseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019cd9de-17b6-7f04-ad7f-71f8c0b96b8c" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_019cd9de-17b6-756e-a334-f6ca61edc155" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019cd9de-17b6-7709-a138-eef53d30ba8a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_019cd9de-17b6-756e-a334-f6ca61edc155" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019cd9de-17b6-7709-a138-eef53d30ba8a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019cd9de-17b6-76ed-a317-1536028fa493" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_019cd9de-17b6-756e-a334-f6ca61edc155" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019cd9de-17b6-76ed-a317-1536028fa493" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019cd9de-17b6-761a-8aa9-2a23c744f2dd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_019cd9de-17b6-756e-a334-f6ca61edc155" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_019cd9de-17b6-761a-8aa9-2a23c744f2dd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019cd9de-17b6-7bee-b827-a5d93fef21b3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019cd9de-17b6-7f04-ad7f-71f8c0b96b8c" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019cd9de-17b6-7bee-b827-a5d93fef21b3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019cd9de-17b6-7170-9a81-9daf0d8dbeef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019cd9de-17b6-7f04-ad7f-71f8c0b96b8c" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019cd9de-17b6-7170-9a81-9daf0d8dbeef" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019cd9de-17b6-74f3-92b4-95a7ca280441" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019cd9de-17b6-7f04-ad7f-71f8c0b96b8c" xlink:to="loc_us-gaap_NetIncomeLoss_019cd9de-17b6-74f3-92b4-95a7ca280441" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInterest_019cd9de-17b6-7f3d-8188-5fa2ff65b00b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentIncomeInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019cd9de-17b6-7f04-ad7f-71f8c0b96b8c" xlink:to="loc_us-gaap_InvestmentIncomeInterest_019cd9de-17b6-7f3d-8188-5fa2ff65b00b" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="simple" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-roles-2025.xsd#eedm"/>
  <link:definitionLink xlink:role="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent" xlink:type="arc" order="31"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent" xlink:type="arc" order="41"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2025/ecd-2025.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/2025/ecd-2025.xsd#ecd_AllIndividualsMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_rng_VladimirShmunisMember_019df088-fa0e-73cf-9e3c-67005f0d728a" xlink:href="rng-20260331.xsd#rng_VladimirShmunisMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_rng_VladimirShmunisMember_019df088-fa0e-73cf-9e3c-67005f0d728a" xlink:type="arc" order="2"/>
  </link:definitionLink>
</link:linkbase>
