Charles City is a city in Floyd County, Iowa, United States. The population was 7,652 at the 2010 census a decrease of 160, or 2%, from 7,812 at the 2000 census. It is the county seat of Floyd County. Charles City is a significant commercial and transportation center for the area, located on U.S. Highways 18 and 218, Iowa Highway 14, and the Canadian National and Iowa, Chicago and Eastern Railroads.