Edgefield, county, western South Carolina, U.S. It consists of a hilly piedmont region bounded to the southwest by the Savannah River border with Georgia. Much of the county is within the southern portion of Sumter National Forest.

Algonquian-speaking Indians inhabited the region in the 1670s. Edgefield county was founded in 1785. It became a centre of political activity and of states’ rights agitation before the American Civil War. The county provided South Carolina with 10 governors and a number of U.S. representatives and senators.

Milk, eggs, and chickens are among the agricultural products, and in most years local orchards produce more peaches than any other county in the state. Logging and lumber mills and the manufacture of clothing and other textile products also are important to the economy. The town of Edgefield is the county seat. Area 502 square miles (1,300 square km). Pop. (2000) 24,588; (2010) 26,985.