The 1988 United States Senate election in Maine was held on November 8, 1988. Incumbent Democratic U.S. Senator George J. Mitchell won re-election to a second full term in a landslide. As of 2023, this is the last time a Democrat has won a U.S. Senate election in Maine.[a] Incumbent Vice President George H.W. Bush won the state in the concurrent presidential election.
^Angus King, who was elected in 2012 and re-elected in 2018, is an independent who caucuses with the Democrats, but is not officially a member of the party.