About This Place
Duncan is a town in Spartanburg County, South Carolina, United States. The population was 3,181 at the 2010 census.
Duncan is located at 34°56′6″N 82°8′5″W / 34.935°N 82.13472°W / 34.935; -82.13472 (34.934983, -82.134801).
According to the United States Census Bureau, the town has a total area of 3.5 square miles (9.1 km²), all of it land.