| Election Name: | 1942 United States Senate election in South Dakota |
| Country: | South Dakota |
| Flag Year: | 1909 |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1936 United States Senate election in South Dakota |
| Previous Year: | 1936 |
| Next Election: | 1948 United States Senate election in South Dakota |
| Next Year: | 1948 |
| Election Date: | November 3, 1942 |
| Image1: | File:BushfieldH.jpg |
| Nominee1: | Harlan J. Bushfield |
| Party1: | Republican Party (United States) |
| Popular Vote1: | 106,704 |
| Percentage1: | 58.74% |
| Nominee2: | Tom Berry |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 74,945 |
| Percentage2: | 41.26% |
| Map Size: | 240px |
| U.S. Senator | |
| Before Election: | William J. Bulow |
| Before Party: | Democratic Party (United States) |
| After Election: | Harlan J. Bushfield |
| After Party: | Republican Party (United States) |
The 1942 United States Senate election in South Dakota took place on November 3, 1942. Incumbent Democratic Senator William J. Bulow ran for re-election to a third term. During the primary, Bulow was attacked for being insufficiently supportive of President Franklin Roosevelt's foreign policy and war preparedness. Former Governor Tom Berry, Bulow's chief opponent, drew a contrast between Bulow's isolationism and his support for Roosevelt's policies.[1] In the end, Berry defeated Bulow in a landslide, and advanced to the general election, where he faced Harlan J. Bushfield, the incumbent Republican Governor of South Dakota. As Republicans gained ground nationwide, Bushfield defeated Berry in a landslide to pick up the seat for the Republican Party. Bushfield did not serve his full term, however; shortly before the 1948 U.S. Senate election, he died.