S59 may refer to: S59 (Long Island bus) S59 (New York City bus), serving Staten Island Dharawal language , a submarine of the Royal Australian Navy , a submarine of the Indian Navy S59: Refer to manufacturer/supplier for information on recovery/recycling, a safety phrase Savoia-Marchetti S.59, an Italian flying boat SIA Engineering Company, a Singaporean aerospace company Sikorsky S-59, a prototype American helicopter