Haymarket is a town in Prince William County, Virginia, United States. The population was 879 at the 2000 census, but the 2009 population estimate is 1,252. Haymarket is home to the Haymarket Senators of the Valley Baseball League. Notable residents include Andray Blatche
Haymarket is located at 38°48′46″N 77°38′6″W / 38.81278°N 77.635°W / 38.81278; -77.635 (38.812670, -77.635084).
According to the United States Census Bureau, the town has a total area of 0.5 square miles (1.3 km²), all of it land.