The 1940 United States Senate election in Massachusetts was held on November 5, 1940, with Democratic incumbent David I. Walsh defeating his challengers.
Democratic primary
Candidates
- David I. Walsh, incumbent U.S. Senator since 1926 (also served 1919–25) and former Governor of Massachusetts (1914–16)
Results
Senator Walsh was unopposed for renomination.
Republican primary
Candidates
- Henry Parkman Jr., Corporation Counsel for the City of Boston, former state senator and Boston City Councilman
Results
Parkman was unopposed for the Republican nomination.
General election
Candidates
- Philip Frankfeld (Communist)
- Horace I. Hillis, perennial candidate (Socialist Labor)
- George Lyman Paine, Episcopal priest and son of philanthropist Robert Treat Paine (Socialist)
- Henry Parkman Jr., Corporation Counsel for the City of Boston, former state senator and Boston City Councilman (Republican)
- George L. Thompson, candidate for governor in 1938 (Prohibition)
- David I. Walsh, incumbent U.S. Senator since 1926 (also served 1919–25) and former governor of Massachusetts (1914–16) (Democratic)