Blountville is a census-designated place (CDP) in and the county chair of Sullivan County, Tennessee, United States. The population was 3,074 at the 2010 census. It is the without help 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 remaining settlement. The site of the town was portion of a tract of more or less 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 chair and conventional a hotel nearby. Blountville was laid off as a town and expected as the county chair in 1795. The county’s first courthouse and jail was a log structure. In 1825 it was replaced taking into consideration a brick building. By 1830, the settlement had 209 residents, two churches, six stores, two taverns, ten mechanics, one doctor, and one lawyer.

On the afternoon of September 22, 1863, during the Civil War, the town was the scene of the four-hour-long Battle of Blountville. During a major expedition into East Tennessee and Southwest Virginia, a Union Army unit attacked Confederate troops at Blountville. The town was shelled in the prosecution and the courthouse was burned in the battle, which goaded the Confederates to withdraw. The courthouse was rebuilt within the old-fashioned walls in 1866. The current courthouse dates from a major construction that was ended in 1920; it as well as includes additions made in 1958.