1930 United States Senate election in South Dakota
The 1930 United States Senate election in South Dakota took place on November 4, 1930. Incumbent Republican Senator William H. McMaster ran for re-election to a second term. After beating back a challenge in the Republican primary from former State Senator George J. Danforth, McMaster faced Democratic nominee William J. Bulow, the incumbent Governor, in the general election. As the Democratic Party performed well nationwide, Bulow narrowly defeated McMaster.