Quantico is a town in Prince William County, Virginia, United States. The population was 480 at the 2010 census. Quantico is approximately 35 miles southwest of Washington, D.C., bordered by the Potomac River to the east and the Quantico Creek to the north. The word Quantico is a corruption of the name of a Doeg village recorded by English colonists as Pamacocack. Quantico is surrounded on its remaining two sides by one of the largest U.S. Marine Corps bases, Marine Corps Base Quantico.