Staten Island ( STAT-ən) is a borough of New York City, coextensive with Richmond County, in the U.S. state of New York. Located in the city's southwest portion, 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 a population of 495,747 in the 2020 Census, Staten Island is the least populated borough but the third largest in land area at 58.5 sq mi (152 km²).

A home to the Lenape indigenous people, the island was settled by Dutch colonists in the 17th century. It was one of the 12 original counties of New York state. Staten Island was consolidated with New York City in 1898. It was formerly known as the Borough of Richmond until 1975, when its name was changed to Borough of Staten Island. 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 island's most urban area. 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+1⁄2-mile (4-kilometer) FDR Boardwalk, the world's fourth-longest boardwalk. The South Shore, site of the 17th-century Dutch and French Huguenot settlement, developed rapidly beginning in the 1960s and 1970s and is now mostly suburban. The West Shore is the island's least populated and most industrial part.

Motor traffic can reach the borough from Brooklyn by the Verrazzano-Narrows Bridge and from New Jersey by the Outerbridge Crossing, Goethals Bridge and Bayonne Bridge. Staten Island has Metropolitan Transportation Authority (MTA) bus lines and an MTA rapid transit line, the Staten Island Railway, which runs from the ferry terminal at St. George to Tottenville. Staten Island is the only borough not connected to the New York City Subway system. The free Staten Island Ferry connects the borough to Manhattan across New York Harbor. It provides views of the Statue of Liberty, Ellis Island, and Lower Manhattan.