Belvidere is a city in Boone County, Illinois, United States. The population was 25,585 as of the 2010 census. It is the county seat of Boone County. Belvidere is part of the Rockford, Illinois Metropolitan Statistical Area. Wrestlers Kasey James External links Belvidere, Illinois Retrieved from "https://prowrestling.fandom.com/wiki/Belvidere,_Illinois?oldid=891992" Categories: American towns Community content is available under CC-BY-SA unless otherwise noted.