Charles City is a city in and the county seat of Floyd County, Iowa, United States. The population was 7,396 at the 2020 census. Charles City is a significant commercial, industrial, and transportation center for the area. U.S. Routes 18, 218, and Iowa Highway 14 converge in the city. The nearest population centers are Mason City, Waterloo-Cedar Falls, and the state capital of Des Moines is located 150 miles to the southwest.