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Massachusetts
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Thomas J. O'Brien

Democratic · Massachusetts · 2026 · Incumbent

Running for Plymouth County Treasurer, Massachusetts

Biography

Thomas J. O'Brien has been Plymouth County Treasurer since 2006 and previously served as state representative for the 12th Plymouth District, per the county treasurer's official pages. As chairman of the Plymouth County Retirement Association he oversees fund assets for more than 9,000 members and 3,300 retirees, per the official pages. No campaign website was found as of September 6, 2026.

On the ballot

Plymouth County TreasurerMassachusetts · 2026Plymouth County sample ballot

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How we source this

Profile facts follow official election office filings and the sources cited in each biography. Roster last verified October 16, 2026. Official sources are the final word on who appears on your ballot.

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