Lake Arbor is an unincorporated area and census-designated place in Prince George's County, Maryland, United States. The population was 14,541 at the 2020 census. The ZIP Codes encompassing the CDP area are 20721 and 20774. In the 1990s, the U.S. Census Bureau defined the area now delineated as Lake Arbor CDP as being in Mitchellville CDP. The Lake Arbor CDP was delineated as of the 2000 U.S. Census.