Cedarville is an unincorporated community and census-designated place in southern Prince George's County, Maryland, United States. As of the 2020 census the population was 639. According to the U.S. Census Bureau, Cedarville had an area of 9.0 square miles, all land. The CDP is bordered to the northwest by Brandywine, to the north by Croom CD…Cedarville is an unincorporated community and census-designated place in southern Prince George's County, Maryland, United States. As of the 2020 census the population was 639. According to the U.S. Census Bureau, Cedarville had an area of 9.0 square miles, all land. The CDP is bordered to the northwest by Brandywine, to the north by Croom CDP, to the east by Baden, and to the south by Charles County.