Dungannon is a town in Scott County, Virginia, United States. The population was 332 at the 2010 census. It was named after the town of Dungannon in County Tyrone, Northern Ireland.Dungannon is part of the Kingsport–Bristol–Bristol 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.