| Election Name: | 1974 United States Senate election in Vermont |
| Country: | Vermont |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1968 United States Senate election in Vermont |
| Previous Year: | 1968 |
| Next Election: | 1980 United States Senate election in Vermont |
| Next Year: | 1980 |
| Image1: | Patrick Leahy 1979 congressional photo.jpg |
| Nominee1: | Patrick Leahy |
| Party1: | Democratic Party (United States) |
| Popular Vote1: | 70,629 |
| Percentage1: | 49.47% |
| Nominee2: | Richard Mallary |
| Party2: | Republican Party (United States) |
| Popular Vote2: | 66,223 |
| Percentage2: | 46.38% |
| Map Size: | 219px |
| U.S. Senator | |
| Before Election: | George Aiken |
| Before Party: | Republican Party (United States) |
| After Election: | Patrick Leahy |
| After Party: | Democratic Party (United States) |
The 1974 United States Senate election in Vermont took place on November 5, 1974. The incumbent Republican Senator, George Aiken, did not run for re-election to another term in the United States Senate. The Democratic nominee, Patrick Leahy, the state's attorney of Chittenden County, defeated Republican nominee, Rep. Richard W. Mallary, to become Aiken's successor. This election also included Liberty Union Party candidate Bernie Sanders, who won 4.1% of the vote.
This election marked the first time in Vermont's history that it elected a Democrat to the U.S. Senate, the last remaining U.S. state to do so. Leahy remained the only Democrat ever elected to the Senate from Vermont until 2022, when he retired and was succeeded by Peter Welch. The last non-Republican elected to the Senate from Vermont before 1974 was Lawrence Brainerd, a Free Soil Party member chosen in 1854 by an anti-slavery coalition of the Vermont General Assembly to fill a brief vacancy in this same seat.