what county is belvidere in il
Belvidere, IL Belvidere ( /bÉlvÉ¨dÉªÉr/) 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. Belvidere is located at 42Â°15â²17â³N 88Â°50â²39â³W / 42.25472Â°N 88.84417Â°W / 42.25472; -88.84417 (42.254758, -88.844093), and sits at an altitude that is approximately 800 feet (240 m) above sea level.