Osage County, Kansas

Osage County
Osage County Courthouse in Lyndon (2009)
Nickname: 
Land of Lakes
Location within the U.S. state of Kansas
Kansas's location within the U.S.
Coordinates: 38°39′N 95°44′W / 38.65°N 95.73°W / 38.65; -95.73
Country United States
State Kansas
Founded1859
Named afterOsage Nation
SeatLyndon
Largest cityOsage City
Area
  Total
720 sq mi (1,900 km2)
  Land706 sq mi (1,830 km2)
  Water14 sq mi (40 km2)  2.0%
Population
 (2020)
  Total
15,766
  Estimate 
(2023)
15,824
  Density22.3/sq mi (8.6/km2)
Time zoneUTC−6 (Central)
  Summer (DST)UTC−5 (CDT)
Congressional district2nd
WebsiteOsageCo.org

Osage County is a county located in the U.S. state of Kansas. Its county seat is Lyndon, and its most populous city is Osage City. As of the 2020 census, the county population was 15,766. The county was originally organized in 1855 as Weller County, then renamed in 1859 after the Osage tribe.