Maynardville (originally named Liberty) is a city in and the county seat of Union County, Tennessee, United States. The city was named to honor Horace Maynard, who successfully defended the creation of Union County from a challenge from Knox County. Its population was 2,413 at the 2010 census, up from 1,782 at the 2000 census. It is included in the Knoxville metropolitan area.