Jefferson County, Wisconsin

county in Wisconsin, United States

Jefferson County is a county in the U.S. state of Wisconsin. As of the 2010 census, the population was 83,686.[1] Its county seat is Jefferson.[2]

Jefferson County
Jefferson County courthouse
Jefferson County courthouse
Map of Wisconsin highlighting Jefferson County
Location within the U.S. state of Wisconsin
Map of the United States highlighting Wisconsin
Wisconsin's location within the U.S.
Coordinates: 43°01′N 88°47′W / 43.02°N 88.78°W / 43.02; -88.78
Country United States
State Wisconsin
Named forJefferson County, New York
Largest cityWatertown
 • Total583 sq mi (1,510 km2)
 • Land556 sq mi (1,440 km2)
 • Water26 sq mi (70 km2)  4.5%
 • Total83,686
 • Estimate 
 • Density140/sq mi (55/km2)
Time zoneUTC−6 (Central)
 • Summer (DST)UTC−5 (CDT)
Congressional district5th


  1. "State & County QuickFacts". United States Census Bureau. Archived from the original on June 6, 2011. Retrieved January 21, 2014.
  2. "Find a County". National Association of Counties. Archived from the original on May 31, 2011. Retrieved June 7, 2011.