The 1972 United States Senate election in Colorado took place on November 7, 1972. Incumbent Republican U.S. Senator Gordon Allott ran for re-election to a fourth term, but was narrowly defeated by Democratic former State Representative Floyd Haskell. This would be the last time until 2008 that a Democrat was elected to the Class 2 Senate seat from Colorado.
1972 United States Senate election in Colorado
Haskell: 40–50% 50–60% 60–70%
Allott: 40–50% 50–60% 60–70%
Floyd Haskell, a former State Representative who had served as a Republican from 1965–67, but had left the party in 1970 over opposition to the Vietnam War, won the primary.