<?xml version="1.0" encoding="UTF-8"?>
<edgarSubmission xmlns="http://www.sec.gov/edgar/npx" xmlns:com="http://www.sec.gov/edgar/common">
  <headerData>
    <submissionType>N-PX</submissionType>
    <filerInfo>
      <registrantType>RMIC</registrantType>
      <liveTestFlag>LIVE</liveTestFlag>
      <filer>
        <issuerCredentials>
          <cik>0000356682</cik>
          <ccc>XXXXXXXX</ccc>
        </issuerCredentials>
      </filer>
      <flags>
        <overrideInternetFlag>false</overrideInternetFlag>
        <confirmingCopyFlag>false</confirmingCopyFlag>
      </flags>
      <investmentCompanyType>N-1A</investmentCompanyType>
      <periodOfReport>06/30/2025</periodOfReport>
    </filerInfo>
    <seriesClass>
      <reportSeriesClass>
        <rptIncludeAllSeriesFlag>true</rptIncludeAllSeriesFlag>
      </reportSeriesClass>
    </seriesClass>
  </headerData>
  <formData>
    <coverPage>
      <yearOrQuarter>YEAR</yearOrQuarter>
      <reportCalendarYear>2025</reportCalendarYear>
      <reportingPerson>
        <name>Calvert Social Investment Fund</name>
        <phoneNumber>2022382200</phoneNumber>
        <address>
          <com:street1>2050 M Street NW</com:street1>
          <com:street2>Suite 200</com:street2>
          <com:city>Washington</com:city>
          <com:stateOrCountry>DC</com:stateOrCountry>
          <com:zipCode>20036</com:zipCode>
        </address>
      </reportingPerson>
      <agentForService>
        <name>Deidre E. Walsh</name>
        <address>
          <com:street1>One Post Office Square</com:street1>
          <com:city>Boston</com:city>
          <com:stateOrCountry>MA</com:stateOrCountry>
          <com:zipCode>02109</com:zipCode>
        </address>
      </agentForService>
      <reportInfo>
        <reportType>FUND VOTING REPORT</reportType>
      </reportInfo>
      <fileNumber>811-03334</fileNumber>
      <explanatoryInformation>
        <explanatoryChoice>Y</explanatoryChoice>
        <explanatoryNotes>The Calvert Conservative Allocation Fund, Calvert Growth Allocation Fund and Calvert Moderate Allocation Fund invest in multiple underlying funds in the Calvert family of funds.  Proxy voting records for the underlying funds can be found on the SEC's website.  The Calvert Bond Fund, The Calvert Conservative Allocation Fund, Calvert Growth Allocation Fund and the Calvert Moderate Allocation Fund did not have any voting activity for this current N-PX period.</explanatoryNotes>
      </explanatoryInformation>
    </coverPage>
    <summaryPage>
      <otherIncludedManagersCount>0</otherIncludedManagersCount>
    </summaryPage>
    <seriesPage>
      <seriesCount>7</seriesCount>
      <seriesDetails>
        <seriesReports>
          <idOfSeries>S000008717</idOfSeries>
          <nameOfSeries>Calvert Balanced Fund</nameOfSeries>
          <leiOfSeries>549300NLUVH82C0C8603</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000008718</idOfSeries>
          <nameOfSeries>Calvert Bond Fund</nameOfSeries>
          <leiOfSeries>549300T75TF7NTCFI791</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000008719</idOfSeries>
          <nameOfSeries>Calvert Equity Fund</nameOfSeries>
          <leiOfSeries>5493008KHIQHXPKPLB89</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000008721</idOfSeries>
          <nameOfSeries>Calvert Conservative Allocation Fund</nameOfSeries>
          <leiOfSeries>549300KT8RN5IFBZID29</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000008722</idOfSeries>
          <nameOfSeries>Calvert Moderate Allocation Fund</nameOfSeries>
          <leiOfSeries>549300ORTNKBKFWWD569</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000008723</idOfSeries>
          <nameOfSeries>Calvert Growth Allocation Fund</nameOfSeries>
          <leiOfSeries>549300UGXJ3LMFVD6U44</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000076003</idOfSeries>
          <nameOfSeries>Calvert Focused Value Fund</nameOfSeries>
          <leiOfSeries>549300Z5XUUT6OW4YT43</leiOfSeries>
        </seriesReports>
      </seriesDetails>
    </seriesPage>
    <signaturePage>
      <reportingPerson>Calvert Social Investment Fund</reportingPerson>
      <txSignature>Von M. Hughes</txSignature>
      <txPrintedSignature>Von M. Hughes</txPrintedSignature>
      <txTitle>President - Principal Executive Officer</txTitle>
      <txAsOfDate>08/19/2025</txAsOfDate>
    </signaturePage>
  </formData>
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