The 1865 United States Senate election in Massachusetts was held during January 1865. Incumbent Republican Senator Henry Wilson was re-elected easily to a second term as a member of the Republican Party.
At the time, Massachusetts elected United States senators by a majority vote of each separate house of the Massachusetts General Court, the House and the Senate.
At the time, the Massachusetts legislature was dominated by the Republican Party, whose members held nearly every seat.
On January 10, the House voted for Wilson's re-election and sent the vote to the Senate for ratification.
On January 20, the State Senate convened and ratified Wilson's re-election by an overwhelming margin.