Rock County, Wisconsin

Rock County
County
Rock County Courthouse
Rock County Courthouse
Official seal of Rock County
Seal
Map of Wisconsin highlighting Rock County
Location within the U.S. state of Wisconsin
Map of the United States highlighting Wisconsin
Wisconsin's location within the U.S.
Coordinates: 42°40′N 89°04′W / 42.67°N 89.07°W / 42.67; -89.07
Country United States
State Wisconsin
Founded1839
Named forRock River
SeatJanesville
Largest cityJanesville
Area
 • Total726 sq mi (1,880 km2)
 • Land718 sq mi (1,860 km2)
 • Water8.0 sq mi (21 km2)  1.1%
Population
 (2020)[1]
 • Total163,687
 • Estimate 
(2023)
164,278 Increase
 • Density230/sq mi (87/km2)
Time zoneUTC−6 (Central)
 • Summer (DST)UTC−5 (CDT)
Congressional districts1st, 2nd
Websitewww.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.

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