Rock County, Wisconsin

Rock County
Rock County
County
	Rock County Courthouse
	Seal
	Location within the U.S. state of Wisconsin
	Wisconsin's location within the U.S.
	Coordinates: 42°40′N 89°04′W / 42.67°N 89.07°W
Country	United States
State	Wisconsin
Founded	1839
Named for	Rock River
Seat	Janesville
Largest city	Janesville
Area
• Total	726 sq mi (1,880 km2)
• Land	718 sq mi (1,860 km2)
• Water	8.0 sq mi (21 km2) 1.1%
Population (2020)
• Total	163,687
• Density	230/sq mi (87/km2)
Time zone	UTC−6 (Central)
• Summer (DST)	UTC−5 (CDT)
Congressional districts	1st, 2nd
Website	www.co.rock.wi.us

Rock County is a county in the U.S. state of Wisconsin. As of the 2020 census, the population was 163,687.^[1] Its county seat is Janesville.^[2] Rock County comprises the Janesville-Beloit, WI Metropolitan Statistical Area and is included in the Madison-Janesville-Beloit, WI Combined Statistical Area.

^ ^a ^b Cite error: The named reference 2020-census-55105 was invoked but never defined (see the help page).
^ "Find a County". National Association of Counties. Retrieved June 7, 2011.