Maynardville is a city that is 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, Tennessee Metropolitan Statistical Area. Maynardville was the birthplace of country music singers Roy Acuff and Carl Smith.