| Election Name: | 1978 United States Senate election in South Dakota |
| Country: | South Dakota |
| Flag Year: | 1963 |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1972 United States Senate election in South Dakota |
| Previous Year: | 1972 |
| Next Election: | 1984 United States Senate election in South Dakota |
| Next Year: | 1984 |
| Election Date: | November 7, 1978 |
| Image1: | File:Larry Pressler as a Congressman.png |
| Nominee1: | Larry Pressler |
| Party1: | Republican Party (United States) |
| Popular Vote1: | 170,832 |
| Percentage1: | 66.84% |
| Nominee2: | Don Barnett |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 84,767 |
| Percentage2: | 33.16% |
| Map Size: | 260px |
| U.S. Senator | |
| Before Election: | James Abourezk |
| Before Party: | Democratic Party (United States) |
| After Election: | Larry Pressler |
| After Party: | Republican Party (United States) |
The 1978 United States Senate election in South Dakota was held on November 7, 1978. Incumbent Democratic U.S. Senator James Abourezk did not run for re-election to a second term, but was succeeded by his political rival,[1] Republican U.S. Representative Larry Pressler.