South Mills is an unincorporated community and census-designated place (CDP) in Camden County, North Carolina, United States. Its population was 454 as of the 2010 census. 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. U.S. Route 17 Business and North Carolina Highway 343 pass through the community.