Blountville is a census-designated place (CDP) in and the county seat^[3] of Sullivan County, Tennessee, United States. The population was 3,074 at the 2010 census.^[4] 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-VACombined Statistical Area – commonly known as the “Tri-Cities” region.