Fremont County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 48,939. The county seat is Cañon City. The county is named for 19th-century explorer and presidential candidate John C. Frémont.
Fremont County comprises the Cañon City, CO Micropolitan Statistical Area, which is also included in the Pueblo-Cañon City, CO Combined Statistical Area.
Rural Fremont County is the location of 15 prisons; most of these are operated by the state. ADX Florence, the only federal Supermax prison in the United States, is in an unincorporated area in Fremont County, south of Florence, and is part of the Federal Correctional Complex, Florence. As of March 2015, Fremont County leads the nation among all counties as the one with the largest proportion of persons incarcerated. Prisoners are counted as part of the county population in the census, and 20% of residents are held in the prisons in the county.