Barnwell County, South Carolina

Barnwell County, South Carolina
Barnwell County Courthouse
Location within the U.S. state of South Carolina
Interactive map of Barnwell County, South Carolina
Coordinates: 33°16′N 81°26′W / 33.26°N 81.43°W / 33.26; -81.43
Country United States
State South Carolina
Founded1800
Named afterJohn Barnwell
SeatBarnwell
Largest communityBarnwell
Area
 • Total
557.26 sq mi (1,443.3 km2)
 • Land548.38 sq mi (1,420.3 km2)
 • Water8.88 sq mi (23.0 km2)  1.59%
Population
 (2020)
 • Total
20,589
 • Estimate 
(2024)
20,495
 • Density37.545/sq mi (14.496/km2)
Time zoneUTC−5 (Eastern)
 • Summer (DST)UTC−4 (EDT)
Congressional district2nd
Websitewww.barnwellcountysc.us

Barnwell County is a county in the U.S. state of South Carolina. As of the 2020 census, its population was 20,589. It is located in the Central Savannah River Area. Its county seat is Barnwell.