what county is lillington, nc  in
Sponsored Topics. Lillington is a town in Harnett County, North Carolina, United States. The population was 2,915 at the 2000 census. It is the county seat of Harnett County. Lillington is located at 35Â°23â²55â³N 78Â°48â²49â³W / 35.39861Â°N 78.81361Â°W / 35.39861; -78.81361 (35.398586, -78.813497).