Brentwood is a town in Prince George's County, Maryland, United States. The population was 3,046 at the 2010 census. Brentwood is less than 1-mile (1.6 km) away from Washington, D.C. The municipality of Brentwood is located just outside the northeast boundary of the District of Columbia and surrounded by the communities of Mount Rainier, Cottage City, North Brentwood, and the nearby Hyattsville.