The 1940 United States Senate election in Maine was held on September 9, 1940.
Incumbent Republican Senator Frederick Hale did not run for re-election. Republican U.S. Representative and former Governor Owen Brewster won the open seat, defeating two Governors of Maine: incumbent Republican Governor Lewis Barrows in the primary and former Democratic Governor Louis Brann in the general election.
Brann was unopposed for the Democratic nomination.