Stephenson County is a county located in the U.S. state of Illinois. As of the most recent data available, the county has a population of approximately 48,979 people, with a population density of about 86.84 persons per square mile.
The county spans a total land area of 564.00 square miles (1,461.00 square kilometers). The administrative center and county seat is Freeport, which often serves as a hub for local governance and services. The largest city within the county by population is Freeport.
Geographically, Stephenson County experiences varied elevations, with its highest point at Lena 960 ft and its lowest point at Winslow 780 ft. The region operates in the UTC-6.