Washington County is a county located in the Commonwealth of Virginia. As of the 2020 United States census, the population was 53,935. Its county seat is Abingdon. Washington County 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 …Washington County is a county located in the Commonwealth of Virginia. As of the 2020 United States census, the population was 53,935. Its county seat is Abingdon. Washington County 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, which includes Bristol TN-VA, Kingsport TN, and Johnson City TN.