Edgefield County is a county located on the western border of the U.S. state of South Carolina. As of the 2020 census, its population was 25,657. Its county seat and largest community is Edgefield. The county was established on March 12, 1785.

Edgefield is a town in and the county seat of Edgefield County, South Carolina, United States. The population was 4,750 at the 2010 census.