Waukegan /wɔːˈkiːɡən/ is the largest city in and the county seat of Lake County, Illinois, United States. It is part of the Chicago Metropolitan Area. As of the 2013 census estimate, the city had a population of 88,826. It is the ninth-largest city in Illinois by population, and it is the fifth-largest city on the western shore of Lake Michigan, after Chicago, Milwaukee, Green Bay, and Kenosha.