Mount Vernon is a census-designated place (CDP) and unincorporated community in Fairfax County, Virginia, United States. The population was 12,416 at the 2010 census. While the name "Mount Vernon"—drawn from the Mount Vernon plantation, the home of George Washington located south of Alexandria—is often used locally to refer to the entire unincorporated area between Old Town Alexandria and Fort Belvoir, Mount Vernon as defined by the Census Bureau encompasses only the portion bounded by the Potomac River to the south, Fort Belvoir to the west, U.S. Route 1 to the north, and Little Hunting Creek to the east.