The 1946 United States Senate election in Montana took place on November 5, 1946. Incumbent United States Senator Burton K. Wheeler, who was first elected to the Senate in 1922, and was re-elected in 1928, 1934, and 1940, ran for re-election. He was challenged in the Democratic primary by Leif Erickson, the Chief Justice of the Montana Supreme Court, and, following a close election, was narrowly defeated by Erickson. In the general election, Erickson faced State SenatorZales Ecton, the Republican nominee. Ultimately, Ecton defeated Erickson by a fairly wide margin, and won his first and only term in the Senate, another Republican would not be elected Senator from Montana for 42 years when Conrad Burns narrowly won the 1988 election.