Oxon Hill is an unincorporated area and census-designated place (CDP) in southern Prince George's County, Maryland, United States. Oxon Hill is a suburb of Washington, D.C. , located southeast of the downtown district and east of Alexandria, Virginia. It is adjacent to the new 300-acre National Harbor development on the shore of the Potomac River. For the 1990 and 2000 censuses, United States Census Bureau defined a census-designated place consisting of Oxon Hill and the adjacent community of Glassmanor, designated Oxon Hill-Glassmanor, for statistical purposes. As of the 2010 census Oxon Hill was delineated separately and had a population of 17,722.