Blountville is a census-designated place (CDP) in and the county seat of Sullivan County, Tennessee, United States. The population was 3,074 at the 2010 census. It is the only Tennessee county seat not to be an incorporated city or town.
Blountville is part of the Kingsport–Bristol (TN)–Bristol (VA) Metropolitan Statistical Area, which is a component of the Johnson City–Kingsport–Bristol, TN-VA Combined Statistical Area – commonly known as the "Tri-Cities" region.
The area that is now Blountville is thought to have been the location of a longhunter fort prior to its permanent settlement. The site of the town was part of a tract of about 600 acres (240 ha) of land bought by James Brigham in 1782. In 1792 Brigham gave 30 acres (12 ha) to Sullivan County for use as a county seat and established a hotel nearby. Blountville was laid off as a town and established as the county seat in 1795. The county's first courthouse and jail was a log structure. In 1825 it was replaced with a brick building.