Hilda is a town in Barnwell County, South Carolina, United States. The population was 447 at the 2010 census.. Hilda is located in eastern Barnwell County at 33°16′26″N 81°14′47″W / 33.27389°N 81.24639°W. South Carolina Highway 70 passes through the town north of its center, leading west 7 miles to Barnwell, the county seat, and east 7 miles t…Hilda is a town in Barnwell County, South Carolina, United States. The population was 447 at the 2010 census.. Hilda is located in eastern Barnwell County at 33°16′26″N 81°14′47″W / 33.27389°N 81.24639°W. South Carolina Highway 70 passes through the town north of its center, leading west 7 miles to Barnwell, the county seat, and east 7 miles to Denmark. South Carolina Highway 304 leads north 5 miles to Blackville.