Kings Park is a census-designated place (CDP) in the town Smithtown, Suffolk County, New York, United States, on Long Island. The population was 17,282 as of the 2010 census. It borders Nissequogue to its east across the river, with Fort Salonga to its west, Commack to its southwest and Smithtown to its east. Kings Park is noted for its schools, numerous parks, and natural beauty. Its tranquility prompted it to be the site of the Kings Park Psychiatric Center instead of New York City.