The 1950 United States Senate election in South Dakota took place on November 7, 1950. Incumbent Republican senator Chan Gurney ran for re-election to a third term. He was challenged in the Republican primary by Congressman Francis H. Case, who had represented the 2nd District since 1939. In the general election, Case faced John A. Engel, an attorney and the 1948 Democratic nominee for the U.S. Senate. As the Republican Party was making significant gains nationwide, Case defeated Engel in a landslide.