Rock County, Wisconsin
Rock County: county in Wisconsin, United States
About
Rock County is a county located in the U.S. state of Wisconsin. As of the 2010 census, the population was 160,331. After 10 years in 2020 county had an estimated population of 163,084 inhabitants. Its county seat is Janesville. The county was created 189 years ago in 1836.
County Snapshot
Rock County at a glance
Rock County currently has 17 quality-checked populated place pages linked on MapSof, making it easier to jump from the county overview into local city pages.
Mapped populated places
17
These counts use a stricter populated-place filter so the main lists stay focused on real city and town pages.
Wisconsin counties
72
Open related pagesLargest city
BeloitPopulation 7,716
Top linked places
Quick Facts about Rock County
| Population | 163,084 (2020) |
| Country | United States of America |
| State | Wisconsin (United States) |
| Different from | Rock County, Rock Island County, Rock County |
| Water as percent of area | 1.1% |
| Land as percent of area | 98.9% |
| Latitude & Longitude | 42.6712,-89.0716 |
| Named for | Rock River, landscape |
| Altitude | 2,648 feet / 807, 249 meters |
| Capital | Janesville |
| Time Zone | America/Chicago |
| Local time | 20:18:23 (15th April 2026) |
| Population growth | 1.69% (2010-2020) |
| Weather | 67℉ Showers And Thunderstorms Likely 7-days weather |
Geography
Rock County is located at 42°40'16"N 89°4'18"W (42.6712200, -89.0715800). It has 7 neighbors: Boone County, Winnebago County, Dane County, Green County, Jefferson County, Walworth County and Washburn County.
Rock County map
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The largest city of Rock County is Beloit with a population of 7,716. Other cities include, Evansville population 5,556, Edgerton population 5,525, Koshkonong population 3,782 and Janesville population 3,612. See all Rock County cities & populated places.
Rock County Populated Places (more)
Cities, towns, neighborhoods & other populated places in Rock County.
| City Name | Population | Title |
|---|---|---|
| Beloit | 7,716 | City in Rock County, Wisconsin, United States |
| Evansville | 5,556 | City in Rock County, Wisconsin, United States |
| Edgerton | 5,525 | City in Rock County, Wisconsin, United States |
| Koshkonong | 3,782 | Civil town in Jefferson County, Wisconsin |
| Janesville | 3,612 | City in and county seat of Rock County, Wisconsin |
| Fulton | 3,435 | Town in Rock County, Wisconsin, United States |
| Milton | 3,126 | City in Rock County, Wisconsin |
| Newark | 1,617 | Civil town in Rock County, Wisconsin |
| Orfordville | 1,486 | Village in Rock County, Wisconsin |
| Clinton | 1,446 | Village in Rock County, Wisconsin, United States |
| Bergen | 1,364 | Unincorporated community in Rock County, Wisconsin |
| Fairfield | 1,104 | Civil town in Sauk County, Wisconsin |
| Footville | 822 | Village in Rock County, Wisconsin |
| Magnolia | 808 | Civil town in Rock County, Wisconsin |
| Johnstown | 791 | Town in Rock County, Wisconsin, United States |
| Tiffany | 650 | City in Wisconsin |
Weather
Showers and thunderstorms likely. Mostly cloudy, with a high near 67. Chance of precipitation is 70%.
7-Day Forecast- Janesville
Demographics
The population of Rock County increased by 1.69% in 10 years.
| Year | Population | % Change | Method |
|---|---|---|---|
| 2010 | 160,331 | - | census |
| 2011 | 159,867 | -0.29% | estimation process |
| 2012 | 160,065 | 0.12% | estimation process |
| 2013 | 160,341 | 0.17% | estimation process |
| 2014 | 160,920 | 0.36% | estimation process |
| 2015 | 161,006 | 0.05% | estimation process |
| 2016 | 161,320 | 0.19% | estimation process |
| 2017 | 162,205 | 0.55% | estimation process |
| 2018 | 162,874 | 0.41% | estimation process |
| 2019 | 163,354 | 0.29% | estimation process |
| 2020 | 163,084 | -0.17% | estimation process |
People born in Rock County (3)
People born in Rock County, including astronomer Olin J. Eggen, REcipient of the Navy Cross Frederick Curtice Davis, US Military Academy superintendent William Durward Connor, .
More notable people
Other places with the same name (2)
- Rock County, Minnesota county in Minnesota, United States of America with a population of 9,301 people.
- Rock County, Nebraska county in Nebraska, United States with a population of 1,377 people.
Wisconsin Other Counties (more counties)
| County Name | Population | Title |
|---|---|---|
| Milwaukee County | 945,016 | County in Wisconsin, United States |
| Milwaukee | 589,067 | The thirtieth most populous city in the United States and the center of the Milwaukee metropolitan area. |
| Dane County | 552,536 | County in Wisconsin, United States |
| Waukesha County | 406,172 | County in Wisconsin, United States |
| Brown County | 264,610 | County in Texas, United States |
| Racine County | 195,802 | County in Wisconsin, United States |
| Outagamie County | 188,766 | County in Wisconsin, United States |
| Winnebago County | 171,631 | County in Wisconsin, United States |
| Kenosha County | 169,671 | County in Wisconsin, United States |
| Washington County | 136,445 | County in Wisconsin, United States |
| Marathon County | 135,593 | County in Wisconsin, United States |
| La Crosse County | 118,502 | County in Wisconsin, United States |
| Sheboygan County | 115,240 | County in Wisconsin, United States |
| Eau Claire County | 105,260 | County in Wisconsin, United States |
| Walworth County | 103,953 | County in Wisconsin, United States |
| Fond du Lac County | 102,902 | County in Wisconsin, United States |