Winnebago County, Illinois
Winnebago County | |
|---|---|
Winnebago County Justice Center | |
Location within the U.S. state of Illinois | |
Illinois's location within the U.S. | |
| Coordinates: 42°20′N 89°10′W / 42.33°N 89.16°W | |
| Country | United States |
| State | Illinois |
| Founded | January 16, 1836 |
| Named after | Winnebago people |
| Seat | Rockford |
| Largest city | Rockford |
| Area | |
• Total | 519 sq mi (1,340 km2) |
| • Land | 513 sq mi (1,330 km2) |
| • Water | 5.9 sq mi (15 km2) 1.1% |
| Population (2020) | |
• Total | 285,350 |
• Estimate (2023) | 280,922 |
| • Density | 550/sq mi (210/km2) |
| Time zone | UTC−6 (Central) |
| • Summer (DST) | UTC−5 (CDT) |
| Congressional districts | 16th, 17th |
| Website | wincoil |
Winnebago County is a county located in the U.S. state of Illinois. According to the 2020 census, it had a population of 285,350 making it the seventh most populous county in Illinois behind Cook County and its five surrounding collar counties. Its county seat is Rockford. Winnebago County is the central county of the Rockford metropolitan area.