Crownsville is a census-designated place (CDP) in Anne Arundel County, Maryland, United States. The population was 1,757 at the 2010 census. It hosts the Anne Arundel County Fair each September, as well as the annual Maryland Renaissance Festival for several summer weekends. A state psychiatric hospital was formerly in Crownsville. The area offers waterfront scenery and easy access to urban metropolitan areas and culture. According to the United States Census Bureau, the CDP has a total area of 5.1 square miles (13.2 km2), all of it land.