| Election Name: | 1974 United States Senate election in Wisconsin |
| Country: | Wisconsin |
| Flag Year: | 1913 |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1968 United States Senate election in Wisconsin |
| Previous Year: | 1968 |
| Next Election: | 1980 United States Senate election in Wisconsin |
| Next Year: | 1980 |
| Election Date: | November 5, 1974 |
| Image1: | GaylordNelson.jpg |
| Nominee1: | Gaylord Nelson |
| Party1: | Democratic Party (United States) |
| Popular Vote1: | 740,700 |
| Percentage1: | 61.75% |
| Nominee2: | Tom Petri |
| Party2: | Republican Party (United States) |
| Popular Vote2: | 429,327 |
| Percentage2: | 35.79% |
| Map Size: | 250px |
| U.S. Senator | |
| Before Election: | Gaylord Nelson |
| Before Party: | Democratic Party (United States) |
| After Election: | Gaylord Nelson |
| After Party: | Democratic Party (United States) |
The 1974 United States Senate election in Wisconsin was held on November 5, 1974. Incumbent Democratic U.S. Senator Gaylord Nelson won re-election to a third term.