The 1934 United States Senate election in Mississippi was held on November 6, 1934. Incumbent Senator Hubert Stephens ran for re-election to a third term, but was defeated by Governor Theodore Bilbo in a close run-off election.
On August 28, Stephens won the Democratic primary over Bilbo and Meridian Congressman Ross Collins in a close three-way race. Since no candidate received a majority of the vote, the election proceeded to a run-off between Stephens and Bilbo. On September 18, Bilbo won the run-off by just 7,115 votes.
Bilbo won the November general election without an opponent.