The 1942 United States elections were held on November 3, 1942, and elected the members of the 75th United States Congress. In Democratic President Franklin D. Roosevelt's unprecedented third mid-term election, the Republican Party picked up seats in both chambers. In the House of Representatives, the Democratic lost forty-five seats, mostly to Republicans. The House elections took place after the 1940 United States Census and the subsequent Congressional re-apportionment. The Democrats also lost eight seats to the Republicans in the U.S. Senate. An Independent also lost his seat to a Republican in the Senate. Despite Republican gains, the Democratic Party retained control of both chambers.
The election was a victory for the conservative coalition, which passed the Smith-Connally Act and abolished the National Resources Planning Board over the objections of Roosevelt.
As the election came in the middle of World War II, voter turnout was just 33.9%. As of 2014, no biennial U.S. election since then has seen a lower voter turnout.