what county is erwin, nc in?
Sponsored Topics. Erwin is a town in Harnett County, North Carolina, United States. The population was 4,537 at the 2000 census. Erwin is located at 35Â°19â²22â³N 78Â°40â²19â³W / 35.32278Â°N 78.67194Â°W / 35.32278; -78.67194 (35.322840, -78.672005).