Waukegan ( wə-KEE-ghən) is a city and county seat of Lake County, Illinois, United States, and an industrial suburb located 36 miles (58 km) north of Chicago. It is the most populous city and . As of the 2020 census, its population was 89,321, making it the seventh-most populous city within the Chicago metropolitan area and the 10th-most populous city in Illinois. Unlike nearby wealthy North Shore suburbs, Waukegan has long been classified by the Illinois state government as overall "socioeconomically distressed" despite having some middle class inhabitants.