<?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>0000751656</cik>
          <ccc>XXXXXXXX</ccc>
          <!--Field: Pseudo-Tag; ID: Name; Data:-->
        </issuerCredentials>
      </filer>
      <flags>
        <overrideInternetFlag>false</overrideInternetFlag>
        <confirmingCopyFlag>false</confirmingCopyFlag>
      </flags>
      <investmentCompanyType>N-1A</investmentCompanyType>
      <periodOfReport>06/30/2026</periodOfReport>
    </filerInfo>
    <seriesClass>
      <reportSeriesClass>
        <rptSeriesClassInfo>
          <seriesId>S000002521</seriesId>
          <!--Field: Pseudo-Tag; ID: Series Name; Data: MFS Alabama Municipal Bond Fund-->
          <includeAllClassesFlag>true</includeAllClassesFlag>
        </rptSeriesClassInfo>
        <rptSeriesClassInfo>
          <seriesId>S000002522</seriesId>
          <!--Field: Pseudo-Tag; ID: Series Name; Data: MFS New York Municipal Bond Fund-->
          <includeAllClassesFlag>true</includeAllClassesFlag>
        </rptSeriesClassInfo>
        <rptSeriesClassInfo>
          <seriesId>S000002523</seriesId>
          <!--Field: Pseudo-Tag; ID: Series Name; Data: MFS North Carolina Municipal Bond Fund-->
          <includeAllClassesFlag>true</includeAllClassesFlag>
        </rptSeriesClassInfo>
        <rptSeriesClassInfo>
          <seriesId>S000002524</seriesId>
          <!--Field: Pseudo-Tag; ID: Series Name; Data: MFS Pennsylvania Municipal Bond Fund-->
          <includeAllClassesFlag>true</includeAllClassesFlag>
        </rptSeriesClassInfo>
        <rptSeriesClassInfo>
          <seriesId>S000002525</seriesId>
          <!--Field: Pseudo-Tag; ID: Series Name; Data: MFS South Carolina Municipal Bond Fund-->
          <includeAllClassesFlag>true</includeAllClassesFlag>
        </rptSeriesClassInfo>
        <rptSeriesClassInfo>
          <seriesId>S000002527</seriesId>
          <!--Field: Pseudo-Tag; ID: Series Name; Data: MFS Virginia Municipal Bond Fund-->
          <includeAllClassesFlag>true</includeAllClassesFlag>
        </rptSeriesClassInfo>
        <rptSeriesClassInfo>
          <seriesId>S000002528</seriesId>
          <!--Field: Pseudo-Tag; ID: Series Name; Data: MFS West Virginia Municipal Bond Fund-->
          <includeAllClassesFlag>true</includeAllClassesFlag>
        </rptSeriesClassInfo>
        <rptSeriesClassInfo>
          <seriesId>S000002529</seriesId>
          <!--Field: Pseudo-Tag; ID: Series Name; Data: MFS Arkansas Municipal Bond Fund-->
          <includeAllClassesFlag>true</includeAllClassesFlag>
        </rptSeriesClassInfo>
        <rptSeriesClassInfo>
          <seriesId>S000002530</seriesId>
          <!--Field: Pseudo-Tag; ID: Series Name; Data: MFS California Municipal Bond Fund-->
          <includeAllClassesFlag>true</includeAllClassesFlag>
        </rptSeriesClassInfo>
        <rptSeriesClassInfo>
          <seriesId>S000002532</seriesId>
          <!--Field: Pseudo-Tag; ID: Series Name; Data: MFS Georgia Municipal Bond Fund-->
          <includeAllClassesFlag>true</includeAllClassesFlag>
        </rptSeriesClassInfo>
        <rptSeriesClassInfo>
          <seriesId>S000002533</seriesId>
          <!--Field: Pseudo-Tag; ID: Series Name; Data: MFS Maryland Municipal Bond Fund-->
          <includeAllClassesFlag>true</includeAllClassesFlag>
        </rptSeriesClassInfo>
        <rptSeriesClassInfo>
          <seriesId>S000002534</seriesId>
          <!--Field: Pseudo-Tag; ID: Series Name; Data: MFS Massachusetts Municipal Bond Fund-->
          <includeAllClassesFlag>true</includeAllClassesFlag>
        </rptSeriesClassInfo>
        <rptSeriesClassInfo>
          <seriesId>S000002535</seriesId>
          <!--Field: Pseudo-Tag; ID: Series Name; Data: MFS Mississippi Municipal Bond Fund-->
          <includeAllClassesFlag>true</includeAllClassesFlag>
        </rptSeriesClassInfo>
        <rptSeriesClassInfo>
          <seriesId>S000002536</seriesId>
          <!--Field: Pseudo-Tag; ID: Series Name; Data: MFS Municipal Income Fund-->
          <includeAllClassesFlag>true</includeAllClassesFlag>
        </rptSeriesClassInfo>
        <rptSeriesClassInfo>
          <seriesId>S000071695</seriesId>
          <!--Field: Pseudo-Tag; ID: Series Name; Data: MFS Municipal Intermediate Fund-->
          <includeAllClassesFlag>true</includeAllClassesFlag>
        </rptSeriesClassInfo>
      </reportSeriesClass>
    </seriesClass>
  </headerData>
  <formData>
    <coverPage>
      <yearOrQuarter>YEAR</yearOrQuarter>
      <reportCalendarYear>2026</reportCalendarYear>
      <reportingPerson>
        <name>MFS MUNICIPAL SERIES TRUST</name>
        <phoneNumber>617-954-5000</phoneNumber>
        <address>
          <com:street1>111 HUNTINGTON AVENUE</com:street1>
          <com:street2>21st FLOOR</com:street2>
          <com:city>BOSTON</com:city>
          <com:stateOrCountry>MA</com:stateOrCountry>
          <com:zipCode>02199</com:zipCode>
        </address>
      </reportingPerson>
      <agentForService>
        <name>Christopher R. Bohane Massachusetts Financial Services Company</name>
        <address>
          <com:street1>111 Huntington Avenue</com:street1>
          <com:city>Boston</com:city>
          <com:stateOrCountry>MA</com:stateOrCountry>
          <com:zipCode>02199</com:zipCode>
        </address>
      </agentForService>
      <reportInfo>
        <reportType>FUND NOTICE REPORT</reportType>
      </reportInfo>
      <fileNumber>811-04096</fileNumber>
      <leiNumber>5493001Q9KE7H84Z5340</leiNumber>
      <explanatoryInformation>
        <explanatoryChoice>Y</explanatoryChoice>
        <explanatoryNotes>On behalf of MFS Alabama Municipal Bond Fund, MFS New York Municipal Bond Fund, MFS North Carolina Municipal Bond Fund, MFS Pennsylvania Municipal Bond Fund, MFS South Carolina Municipal Bond Fund, MFS Virginia Municipal Bond Fund, MFS West Virginia Municipal Bond Fund, MFS Arkansas Municipal Bond Fund, MFS California Municipal Bond Fund, MFS Georgia Municipal Bond Fund, MFS Maryland Municipal Bond Fund, MFS Massachusetts Municipal Bond Fund, MFS Mississippi Municipal Bond Fund, MFS Municipal Income Fund, and MFS Municipal Intermediate Fund (the "funds"), all series of MFS Municipal Series Trust, there are no proxy voting activity for the funds, as the funds did not hold any votable positions during the reporting period.</explanatoryNotes>
      </explanatoryInformation>
    </coverPage>
    <seriesPage>
      <seriesCount>15</seriesCount>
      <seriesDetails>
        <seriesReports>
          <idOfSeries>S000002521</idOfSeries>
          <nameOfSeries>MFS Alabama Municipal Bond Fund</nameOfSeries>
          <leiOfSeries>M7CC6KLX5LX4YG4Z0676</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000002522</idOfSeries>
          <nameOfSeries>MFS New York Municipal Bond Fund</nameOfSeries>
          <leiOfSeries>VBDLXONWHCNFU9SKO405</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000002523</idOfSeries>
          <nameOfSeries>MFS North Carolina Municipal Bond Fund</nameOfSeries>
          <leiOfSeries>Y3HMANBD6AL3XSXU2W16</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000002524</idOfSeries>
          <nameOfSeries>MFS Pennsylvania Municipal Bond Fund</nameOfSeries>
          <leiOfSeries>8MG4769ZL455HON5LD92</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000002525</idOfSeries>
          <nameOfSeries>MFS South Carolina Municipal Bond Fund</nameOfSeries>
          <leiOfSeries>08HGTHG281BFQRFCD148</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000002527</idOfSeries>
          <nameOfSeries>MFS Virginia Municipal Bond Fund</nameOfSeries>
          <leiOfSeries>ZBE08E46OUHKF4OZUH15</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000002528</idOfSeries>
          <nameOfSeries>MFS West Virginia Municipal Bond Fund</nameOfSeries>
          <leiOfSeries>W36WJXZ97WII7K64W483</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000002529</idOfSeries>
          <nameOfSeries>MFS Arkansas Municipal Bond Fund</nameOfSeries>
          <leiOfSeries>IBCRCKLUQF4H2CCTDD70</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000002530</idOfSeries>
          <nameOfSeries>MFS California Municipal Bond Fund</nameOfSeries>
          <leiOfSeries>HJJE4BDRSB2UZB44II16</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000002532</idOfSeries>
          <nameOfSeries>MFS Georgia Municipal Bond Fund</nameOfSeries>
          <leiOfSeries>D6T6CE9XSLIZ37D0OB07</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000002533</idOfSeries>
          <nameOfSeries>MFS Maryland Municipal Bond Fund</nameOfSeries>
          <leiOfSeries>NDK106CDS4LPS37O1K93</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000002534</idOfSeries>
          <nameOfSeries>MFS Massachusetts Municipal Bond Fund</nameOfSeries>
          <leiOfSeries>MI3C3CKY7VNRDNDWCO87</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000002535</idOfSeries>
          <nameOfSeries>MFS Mississippi Municipal Bond Fund</nameOfSeries>
          <leiOfSeries>4GAB1OTSRRZ89GG72J95</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000002536</idOfSeries>
          <nameOfSeries>MFS Municipal Income Fund</nameOfSeries>
          <leiOfSeries>EX1INFNFQVRO3N97PT04</leiOfSeries>
        </seriesReports>
        <seriesReports>
          <idOfSeries>S000071695</idOfSeries>
          <nameOfSeries>MFS Municipal Intermediate Fund</nameOfSeries>
          <leiOfSeries>549300PSMWF1MUF80F76</leiOfSeries>
        </seriesReports>
      </seriesDetails>
    </seriesPage>
    <signaturePage>
      <reportingPerson>MFS MUNICIPAL SERIES TRUST</reportingPerson>
      <txSignature>David DiLorenzo</txSignature>
      <txPrintedSignature>David DiLorenzo</txPrintedSignature>
      <txTitle>President and Principal Executive Officer</txTitle>
      <txAsOfDate>08/26/2026</txAsOfDate>
    </signaturePage>
  </formData>
</edgarSubmission>
