Brown County, South Dakota

Brown County
Location within the U.S. state of South Dakota
South Dakota's location within the U.S.
Coordinates: 45°35′21.314″N 98°21′7.83″W / 45.58925389°N 98.3521750°W / 45.58925389; -98.3521750
Country United States
State South Dakota
FoundedJuly 6, 1881
Named afterAlfred Brown
SeatAberdeen
Largest cityAberdeen
Area
  Total
1,730.951 sq mi (4,483.14 km2)
  Land1,713.030 sq mi (4,436.73 km2)
  Water17.921 sq mi (46.42 km2)  1.0%
Population
 (2020)
  Total
38,301
  Estimate 
(2024)
37,495
  Density22.027/sq mi (8.505/km2)
Time zoneUTC−6 (Central)
  Summer (DST)UTC−5 (CDT)
Congressional districtAt-large
Websitebrown.sd.us

Brown County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 38,301, making it the fourth most populous county in South Dakota, and was estimated to be 37,495 in 2024. Its county seat is Aberdeen. The county is named for Alfred Brown, of Hutchinson County, South Dakota, a Dakota Territory legislator in 1879.

Brown County is part of the Aberdeen, SD Micropolitan Statistical Area.