S54 may refer to:
Aircraft Blériot-SPAD S.54, a French biplane trainer Sikorsky S-54, an American helicopter Sukhoi S-54, a proposed Russian trainer aircraft
Other uses S54 (Long Island bus) S54 (New York City bus), serving Staten Island BMW S54, an automobile engine Prince Skyline (S54), a Japanese sedan Ronga language, a Bantu language Shorland S54, a British armoured car Walbunja language, an Australian Aboriginal language Toyota S54, a Toyota S transmission model