[2] It was named after the town of Dungannon in County Tyrone, Northern Ireland.

Dungannon is part of the Kingsport-Bristol-Bristol, TN-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 Flanary Archeological Site was listed on the National Register of Historic Places in 1983.

[6] According to the United States Census Bureau, the town has a total area of 0.4 square miles (1.0 km2), all of it land.

At the 2000 census there were 317 people, 132 households, and 90 families living in the town.