Gunnison is a home rule municipality that is the county seat of and the most populous municipality in Gunnison County, Colorado, United States. The city population was 6,560 at the 2020 United States census. The city was named in honor of John W. Gunnison, a United States Army officer who surveyed for a transcontinental railroad in 1853. Gunnison is a college town, home to Western Colorado University.