Dumfries is a town in Prince William County, Virginia, United States. The population was 4,937 at the 2000 census.
Dumfries is located at 38°34′4″N 77°19′29″W / 38.56778°N 77.32472°W / 38.56778; -77.32472 (38.567853, -77.324591).
According to the United States Census Bureau, the town has a total area of 1.6 square miles (4.1 km²), all of it land. The town is situated about 28 miles south of Washington D.C.