Red Hill is a census-designated place in Horry County, South Carolina, United States. The population was 13,223 at the 2010 census, up from 10,509 at the 2000 census. Red Hill is in south-central Horry County at 33°47′18″N 79°0′49″W / 33.78833°N 79.01361°W. It is bordered to the north by the city of Conway, the county seat, and to the south by Soc…Red Hill is a census-designated place in Horry County, South Carolina, United States. The population was 13,223 at the 2010 census, up from 10,509 at the 2000 census. Red Hill is in south-central Horry County at 33°47′18″N 79°0′49″W / 33.78833°N 79.01361°W. It is bordered to the north by the city of Conway, the county seat, and to the south by Socastee. U.S. Route 501 passes through the northern part of Red Hill, connecting Conway to the north with Myrtle Beach, 12 miles to the southeast. South Carolina Highway 544 runs north–south the length of Red Hill, connecting Conway with Socastee. The west side of Red Hill is bordered by the Waccamaw National Wildlife Refuge.