Big Pool is an unincorporated community in western Washington County, Maryland, United States. It is between Clear Spring, Maryland and Hancock, Maryland along U.S. Route 40 and is officially a part of the Hagerstown Metropolitan Area. To the south of Big Pool lies Fort Frederick State Park, a restored fort used during the French and Indian War. Also nearby is the Chesapeake and Ohio Canal National Historical Park, which lies near Ft. Frederick alongside the Potomac River.