Tantallon is an unincorporated community in Prince George's County, Maryland, United States. Although a separate community, it is a part of the census-designated place (CDP) of Fort Washington. The ZIP code for the community is 20744. Tantallon reported as a census-designated place by the U.S. Census Bureau in 1980, which included much of the northern half of Fort Washington's census area. The population recorded was 9,945.