Stephenson County, Illinois

Stephenson County, Illinois
Location within the U.S. state of Illinois
Coordinates: 42°21′N 89°40′W / 42.35°N 89.67°W / 42.35; -89.67
Country United States
State Illinois
Founded1837
Named afterBenjamin Stephenson
SeatFreeport
Largest cityFreeport
Area
 • Total
565 sq mi (1,460 km2)
 • Land565 sq mi (1,460 km2)
 • Water0.5 sq mi (1.3 km2)  0.09%
Population
 (2020)
 • Total
44,630
 • Estimate 
(2024)
43,088
 • Density79.0/sq mi (30.5/km2)
Time zoneUTC−6 (Central)
 • Summer (DST)UTC−5 (CDT)
Congressional districts16th, 17th
Websitewww.co.stephenson.il.us

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.