Lake 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 644,356 people, with a population density of about 438.29 persons per square mile.
The county spans a total land area of 448.00 square miles (1,160.00 square kilometers). The administrative center and county seat is Waukegan, which often serves as a hub for local governance and services. The largest city within the county by population is Waukegan.
Geographically, Lake County experiences varied elevations, with its highest point at Lake Zurich 880 ft and its lowest point at Winthrop Harbor 650 ft. The region operates in the UTC-6.