Day County, South Dakota

Day County
Location within the U.S. state of South Dakota
South Dakota's location within the U.S.
Coordinates: 45°22′N 97°37′W / 45.37°N 97.61°W / 45.37; -97.61
Country United States
State South Dakota
Founded1880
Named afterMerritt H. Day
SeatWebster
Largest cityWebster
Area
  Total
1,091 sq mi (2,830 km2)
  Land1,028 sq mi (2,660 km2)
  Water63 sq mi (160 km2)  5.8%
Population
 (2020)
  Total
5,449
  Estimate 
(2024)
5,408
  Density5.0/sq mi (1.9/km2)
Time zoneUTC−6 (Central)
  Summer (DST)UTC−5 (CDT)
Congressional districtAt-large
Websiteday.sdcounties.org

Day County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 5,449. Its county seat is Webster. The county is named for Merritt H. Day, pioneer and 1879 Dakota Territory legislator.