About Lillington NC Lillington, North Carolina is the seat for Harnett County, yet it is quaint in its small-town charm, with about 3,600 residents. This town is the perfect choice for those who enjoy being on a first-name basis with neighbors. From the most unique coffee shops or farmer's markets to walking down South Main Street, be prepared for friendly waves and many conversations. Continue to read to find the best reasons for choosing Lillington, NC as your home base.