South Mills is an unincorporated community and census-designated place (CDP) in Camden County, North Carolina, United States. As of the 2020 census, South Mills had a population of 362. South Mills has a post office with ZIP code 27976, which opened on March 2, 1840. The community is located near U.S. Route 17, and U.S. Route 17 Business and North Carolina Highway 343, and future Interstate 87 pass through the community.