Winnebago County | |
|---|---|
 Winnebago County Justice Center | |
 Seal | |
 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 for | 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.[1] Winnebago County is the central county of the Rockford metropolitan area.
- ^ "Find a County". National Association of Counties. Retrieved June 7, 2011.