Hamlin County, South Dakota

Hamlin County
Hamlin County Courthouse in Hayti in 1974
Location within the U.S. state of South Dakota
South Dakota's location within the U.S.
Coordinates: 44°41′N 97°12′W / 44.68°N 97.2°W / 44.68; -97.2
Country United States
State South Dakota
Founded1873 (created)
1878 (organized)
Named afterHannibal Hamlin
SeatHayti
Largest cityEstelline
Area
  Total
538 sq mi (1,390 km2)
  Land507 sq mi (1,310 km2)
  Water31 sq mi (80 km2)  5.7%
Population
 (2020)
  Total
6,164
  Estimate 
(2024)
6,596
  Density11/sq mi (4.4/km2)
Time zoneUTC−6 (Central)
  Summer (DST)UTC−5 (CDT)
Congressional districtAt-large
Websitehamlinco.us

Hamlin County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 6,164. Its county seat is Hayti. The county was created in 1873 and organized in 1878. It was named for Hannibal Hamlin, Lincoln's first vice-president.