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.
- William J. Bulow, Governor of South Dakota
- James McNamara, former State Senator from Beadle County
|Democratic||William J. Bulow||16,520||73.88%|
- William H. McMaster, incumbent U.S. Senator
- George J. Danforth, former State Senator from Minnehaha County
|Republican||William H. McMaster (inc.)||64,331||55.92%|
|Republican||George J. Danforth||50,717||44.08%|
|Democratic||William J. Bulow||106,317||51.63%||+20.39%|
|Republican||William H. McMaster (inc.)||99,595||48.37%||+4.24%|
|Democratic gain from Republican|
- "Anti-Bulow Demos Gather: McNamara, Davenport And Everson Believed Likely Material For Senate Race". Evening Huronite. Huron, S.D. March 17, 1930. p. 1. Retrieved June 10, 2021.
- Nelson, Nelson; Heinrich, Chad W., eds. (2005). "Chapter 8: Elections". Legislative Manual: South Dakota, 2005. Pierre, S.D. p. 627.
- "Danforth Announces Candidacy for Senate Nomination: Sioux Falls Man Issues Official Statement Today". Argus Leader. Sioux Falls, S.D. February 11, 1930. p. 1. Retrieved June 10, 2021.