Greenbelt is a city in Prince George's County, Maryland, United States. Contained within today's City of Greenbelt is the historic planned community now known locally as "Old Greenbelt" and designated as the Greenbelt Historic District. Greenbelt's population was 23,068 at the 2010 U.S. Census.
Greenbelt is known widely as a public cooperative community founded in the New Deal era. Greenbelt was one of three "green" towns planned in 1935 under the United States Resettlement Administration, along with Greendale, Wisconsin and Greenhills, Ohio.