The county seat is Lillington, a small town of about 4,000 residents. The largest town is Fuquay-Varina, which has around 35,000 people (with a big portion of the town actually in Wake County). Dunn is the next biggest with about 9,000 residents and serves as a commercial hub on the eastern side. Coats has roughly 2,500 people, while Angier (partly in Wake County) and Erwin each sit around 5,000–6,000.

Other notable communities include Spivey’s Corner, Buies Creek (home to Campbell University), and several unincorporated areas. The total population of Harnett County is approximately 140,000, and it’s been one of the faster-growing counties in the state thanks to its location between the Triangle and Fayetteville. It blends suburban neighborhoods near Raleigh with traditional small towns and rural countryside across the rest of the county.