Kings Island is an island in the Old River (California) in the south Sacramento-San Joaquin River Delta in San Joaquin County, California, fifteen kilometres southwest of Stockton. The small 3.5 ha (8.6-acre) island is the smallest of a cluster of delta islands including Eucalyptus Island, Widdows Island, Victoria Island (California), and Coney Island, adjacent to Clifton Court Forebay. At 1 metre below sea level with the surrounding waters kept a bay by a levee system, and is accessible only by the one road from the Clifton Court levee or by boat.