S55

S55 may refer to:

Aircraft

• Savoia-Marchetti S.55, an Italian flying boat
• Sikorsky S-55, an American helicopter
• Sukhoi S-55, a proposed Russian fighter aircraft

Automobiles

• BMW S55, an automobile engine
• Mercedes-Benz S 55 AMG, a luxury car
• Mercury S-55, an American full-size car
• Shorland S55, a British armoured personnel carrier

Rail and transit

• S55 (New York City bus) serving Staten Island
• S55 (St. Gallen S-Bahn), a former S-Bahn line in Thurgau, Switzerland
• S55 (ZVV), a former line of the Zürich S-Bahn
• FGC line S55, a suburban train line in Catalonia, Spain

Other uses

• S55 (star) in the constellation Sagittarius
• Ariel 1, a British satellite
• County Route S55 (Bergen County, New Jersey)
• Explorer S-55 (satellite), a failed American spacecraft
• INS Sindhughosh (S55), a submarine of the Indian Navy
• Siemens S55, a mobile phone
• Wandandian language