Waukegan ( /wɔːkiːɡən/) is a city and county seat of Lake County, Illinois. As of the 2000 census, the city had a total population of 87,901. The 2010 population was 89,078. It is the ninth-largest city in Illinois by population. It is the fifth-largest city on the western shore of Lake Michigan, after Chicago, Milwaukee, Green Bay, and Kenosha.
Waukegan is located at 42°22′21″N 87°51′41″W / 42.3725°N 87.86139°W / 42.3725; -87.86139 (42.372471, -87.861521). Waukegan is on the shore of Lake Michigan, about 8 miles (13 km) south of the border with Wisconsin and 40 miles (64 km) north of downtown Chicago, at an elevation of about 669 feet (204 m) above sea level.
According to the United States Census Bureau, the city has a total area of 23.1 square miles (59.8 km²). 23.0 square miles (59.6 km²) of it is land and 0.1 square miles (0.2 km²) of it (0.35%) is water.