Oconee County is the westernmost county in the U.S. state of South Carolina. As of the 2020 census, the population was 78,607. Its county seat is Walhalla and its largest community is Seneca. Oconee County is included in the Seneca, SC Micropolitan Statistical Area, which is also included in the Greenville-Spartanburg-Anderson, SC Combined Statistical Area. South Carolina Highway 11, the Cherokee Foothills National Scenic Highway, begins in southern Oconee County at Interstate Highway 85 at the Georgia state line.

Walhalla is a city in the foothills of the Blue Ridge Mountains in Oconee County, South Carolina. Designated in 1868 as the county seat, it lies within the area of the Blue Ridge Escarpment, an area of transition between mountains and piedmont, and contains numerous waterfalls. It is located 16 miles (26 km) from Clemson University in Clemson, South Carolina.