Stephenson County, Illinois
| Stephenson County | |
|---|---|
| Location within the U.S. state of Illinois | |
| Illinois's location within the U.S. | |
| Coordinates: 42°21′N 89°40′W / 42.35°N 89.67°W | |
| Country | United States | 
| State | Illinois | 
| Founded | 1837 | 
| Named after | Benjamin Stephenson | 
| Seat | Freeport | 
| Largest city | Freeport | 
| Area | |
|  • Total | 565 sq mi (1,460 km2) | 
| • Land | 565 sq mi (1,460 km2) | 
| • Water | 0.5 sq mi (1 km2) 0.09% | 
| Population  (2020) | |
|  • Total | 44,630 | 
|  • Estimate  (2023) | 43,105 | 
| • Density | 79/sq mi (30/km2) | 
| Time zone | UTC−6 (Central) | 
| • Summer (DST) | UTC−5 (CDT) | 
| Congressional districts | 16th, 17th | 
| Website | www | 
Stephenson County is a county located in the U.S. state of Illinois. According to the 2020 United States census, it had a population of 44,630. Its county seat is Freeport. Stephenson County is included in the Freeport, IL Micropolitan Statistical Area, which is also included in the Rockford-Freeport-Rochelle, IL Combined Statistical Area.