Staten Island () is a borough of New York City, coterminous with Richmond County, in the U.S. state of New York. Located in the southwest portion of the city, the borough is separated from New Jersey by the Arthur Kill and the Kill Van Kull and from the rest of New York by New York Bay. With an estimated population of 476,143 in 2019, Staten Island is the least populated of the boroughs but is the third-largest in land area at 58.5 sq mi (152 km2). The borough also contains the southern-most point in the state, South Point. If each borough were ranked as a city, Staten Island would rank as the 39th most populous in the U.S.
Staten Island joined New York City in 1898, and was referred to as the Borough of Richmond until 1975. Staten Island has sometimes been called "the forgotten borough" by inhabitants who feel neglected by the city government.
The North Shore—especially the neighborhoods of St. George, Tompkinsville, Clifton, and Stapleton—is the most urban part of the island; it contains the designated St. George Historic District and the St. Paul's Avenue-Stapleton Heights Historic District, which feature large Victorian houses. The East Shore is home to the 2.5-mile (4 km) F.D.R. Boardwalk, the fourth-longest boardwalk in the world.