Chardon is a city in and the county seat of Geauga County, Ohio, United States. The population was 5,242 at the 2020 census. It is the only in…Chardon is a city in and the county seat of Geauga County, Ohio, United States. The population was 5,242 at the 2020 census. It is the only incorporated city in Geauga County, and includes land that was once part of Chardon, Hambden and Munson townships. It is located about 10 miles south of Lake Erie and within the "snow belt" of the Great Lakes and is part of the Cleveland metropolitan area.