| Election Name: | 1938 United States Senate elections in South Dakota |
| Country: | South Dakota |
| Flag Year: | 1909 |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1932 United States Senate election in South Dakota |
| Previous Year: | 1932 |
| Next Election: | 1944 United States Senate election in South Dakota |
| Next Year: | 1944 |
| Election Date: | November 8, 1938 |
| Image1: | John Chandler Gurney.jpg |
| Nominee1: | Chan Gurney |
| Party1: | Republican Party (United States) |
| Popular Vote1: | 146,813 |
| Percentage1: | 52.46% |
| Nominee2: | Tom Berry |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 133,064 |
| Percentage2: | 47.54% |
| Map Size: | 240px |
| U.S. Senator | |
| Before Election: | Herbert E. Hitchcock |
| Before Party: | Democratic Party (United States) |
| After Election: | Chan Gurney |
| After Party: | Republican Party (United States) |
The 1938 United States Senate elections in South Dakota took place on November 8, 1938. Incumbent Republican Senator Peter Norbeck died in office on December 20, 1936. Herbert E. Hitchcock was appointed by Governor Tom Berry as Norbeck's replacement. Two elections for the same Senate seat were held on the same day; one as a special election to fill the remainder of Norbeck's six-year term, and another to select a Senator to serve the next six-year term.
In the regularly scheduled election, Hitchcock ran for election for a full term, but was overwhelmingly defeated in the Democratic primary by former Governor Berry. In the Republican primary, businessman Chan Gurney won a slim plurality in a crowded primary. Gurney narrowly defeated Berry to win his first of two terms in the Senate. In the special election for the final few months of Norbeck's term, former Secretary of State Gladys Pyle won the Republican nomination unopposed, and Thomas W. Crawford won the Democratic nomination unopposed. However, following Crawford's death, the state Democratic Party named John T. McCullen as its replacement nominee. Pyle defeated McCullen in a landslide, becoming the first woman to represent South Dakota in the United States Senate.
Thomas M. Crawford was the only Democratic candidate to file for the special election, thereby removing the primary election from the ballot and granting him the nomination by default.[1] However, after the primary election took place, Crawford died. The Democratic Party of South Dakota named John T. McCullen, a former State Senator from Hand County,[2] as its replacement nominee.[3]
Former Secretary of State Gladys Pyle announced that she would run for the Republican nomination for the special election.[6] She, like Crawford, won the Republican nomination unopposed and the race did not appear on the primary election ballot.[1]