| Election Name: | 1980 United States Senate election in Iowa |
| Country: | Iowa |
| Flag Image: | Flag of Iowa (xrmap collection).svg |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1974 United States Senate election in Iowa |
| Previous Year: | 1974 |
| Next Election: | 1986 United States Senate election in Iowa |
| Next Year: | 1986 |
| Election Date: | November 4, 1980 |
| Image1: | File:Chuck Grassley 1979 congressional photo.jpg |
| Nominee1: | Chuck Grassley |
| Party1: | Republican Party (United States) |
| Popular Vote1: | 683,014 |
| Percentage1: | 53.49% |
| Nominee2: | John Culver |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 581,545 |
| Percentage2: | 45.54% |
| Map Size: | 240px |
| U.S. Senator | |
| Before Election: | John Culver |
| Before Party: | Democratic Party (United States) |
| After Election: | Chuck Grassley |
| After Party: | Republican Party (United States) |
The 1980 United States Senate election in Iowa was held on November 4, 1980. Incumbent Democratic United States Senator John Culver ran for reelection to a second term, but lost to Republican nominee Chuck Grassley, the United States Congressman from Iowa's 3rd congressional district. This election marked the beginning of eight consecutive victories for Grassley in the Senate. It remains the closest election of his Senate career.