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 35°23′55″N 78°48′49″W / 35.39861°N 78.81361°W / 35.39861; -78.81361 (35.398586, -78.813497).
According to the United States Census Bureau, the town has a total area of 4.0 square miles (10.4 km²), of which, 4.0 square miles (10.3 km²) of it is land and 0.04 square miles (0.1 km²) of it (0.99%) is water.