| Election Name: | 1956 United States Senate election in South Dakota |
| Country: | South Dakota |
| Flag Year: | 1909 |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1950 United States Senate election in South Dakota |
| Previous Year: | 1950 |
| Next Election: | 1962 United States Senate election in South Dakota |
| Next Year: | 1962 |
| Election Date: | November 6, 1956 |
| Nominee1: | Francis H. Case |
| Party1: | Republican Party (United States) |
| Popular Vote1: | 147,621 |
| Percentage1: | 50.79% |
| Nominee2: | Kenneth Holum |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 143,001 |
| Percentage2: | 49.21% |
| Map Size: | 240px |
| U.S. Senator | |
| Before Election: | Francis H. Case |
| Before Party: | Republican Party (United States) |
| After Election: | Francis H. Case |
| After Party: | Republican Party (United States) |
The 1956 United States Senate election in South Dakota took place on November 6, 1956. Incumbent Republican Senator Francis H. Case ran for re-election to a second term. In the general election, Case was opposed by former State Representative Kenneth Holum, who was the 1954 Democratic nominee for the U.S. Senate. Owing in part to anger among the state's farmers,[1] the race between Case and Holum was quite close,[2] with Holum leading Case on election night and only falling behind the next day. Case ended up narrowly winning re-election,[3] defeating Holum by just 4,620 votes.
Incumbent U.S. Senator Francis H. Case was the only Republican candidate to file for the U.S. Senate, removing the race from the primary ballot.[6]