Founded in 1837, Boone County is one of 102 counties in the state of Illinois. Historically, Boone County was formed from Winnebago County. The city of Belvidere is the county seat. With FIPS code of 7, Boone County has a population of 53,159 and area of 280 square miles (725 km2).
List of all cities in Boone County, IL alphabetically
| City/Town | Postal Code | Area Code |
| Argyle, IL | 61011 | 815/779 |
| Belvidere, IL | 61008 | 815/779 |
| Blaine, IL | 61065 | 815/779 |
| Bonus, IL | 61038 | 815/779 |
| Caledonia, IL | 61011 | 815/779 |
| Candlewick Lake, IL | 61065 | 815/779 |
| Capron, IL | 61012 | 815/779 |
| Garden Prairie, IL | 61038 | 815/779 |
| Poplar Grove, IL | 61065 | 815/779 |