Lake County, Illinois

Lake County
County
Lake County Courthouse in Waukegan
Flag Seal Logo
Nickname:  L.C.
Location within the U.S. state of Illinois
Illinois's location within the U.S.
Coordinates: 42°26′N 87°47′W / 42.43°N 87.78°W / 42.43; -87.78
Country	United States
State	Illinois
Founded	March 1, 1839
Named for	Lake Michigan
Seat	Waukegan
Largest city	Waukegan
Area
• Total	1,368 sq mi (3,540 km2)
• Land	444 sq mi (1,150 km2)
• Water	925 sq mi (2,400 km2)  67.6%
Population  (2020)
• Total	714,342
• Estimate  (2023)	708,760
• Density	1,596.31/sq mi (616.34/km2)
Time zone	UTC−6 (Central)
• Summer (DST)	UTC−5 (CDT)
Congressional districts	5th, 9th, 10th, 11th
Website	www.lakecountyil.gov

Lake County is a county located in the northeastern corner of the U.S. state of Illinois, along the shores of Lake Michigan. As of the 2020 census, it has a population of 714,342,^[1] making it the third-most populous county in Illinois. Its county seat is Waukegan, the tenth-largest city in Illinois.^[2] The county is primarily suburban, with some urban areas and some rural areas. Due to its location, immediately north of Cook County, Lake County is one of the collar counties of the Chicago metropolitan area. Its northern boundary is the Wisconsin state line.

According to the 2010 census, Lake County is the second wealthiest county in the state by per capita income, after DuPage County. Additionally, Lake County ranks as the 27th wealthiest county in the nation. The county includes the affluent North Shore communities of Lake Forest, Lake Bluff, and Highland Park, and much of the county's wealth is concentrated in this area, as well as in communities bordering Cook County to the south and McHenry County to the west. The north and northwest areas of the county, though historically rural and exurban, have experienced rapid suburbanization in the past three decades, while the lakefront communities of Waukegan, North Chicago, and Zion are postindustrial areas that have majority-minority populations. The Hispanic population has seen significant increases in nearly all areas of the county and comprise 24% of the county's population in 2020. Naval Station Great Lakes is located in the city of North Chicago. It is the United States Navy's Headquarters Command for training, and the Navy's only recruit training center.