Marlton is an unincorporated area and census-designated place in Prince George's County, Maryland, United States. The population was 9,802 at the 2020 census. The Marlton housing development, at first briefly called "Brandywine Country", grew up along U.S. Route 301 in the 1970s, and is part of the greater Upper Marlboro community. Originally made up of only single-family homes, more recently townhouses have been added.