S33

S33 may refer to:

Aviation

 * Blériot-SPAD S.33, a French airliner
 * Letov Š-33, a Czechoslovak bomber
 * Madras Municipal Airport, in Jefferson County, Oregon, United States
 * Short S.33, a British flying boat
 * Sikorsky S-33 Messenger, an American sesquiplane
 * Spectrum S-33 Independence, an American business jet

Naval vessels

 * BRAZILIAN SUBMARINE Tapajó
 * SMS S33 (1914), a torpedo boat of the Imperial German Navy
 * SPANISH SUBMARINE Narcíso Monturiol
 * USS S-33 (SS-138), a submarine of the United States Navy

Other uses

 * S33 (Long Island bus)
 * S33 (ZVV), a line of the Zürich S-Bahn
 * County Route S33 (Bergen County, New Jersey)
 * S33: Take precautionary measures against static discharges, a safety phrase
 * Section 33 of the Canadian Charter of Rights and Freedoms
 * Sotho language
 * Sulfur-33, an isotope of sulfur
 * S33, a postcode district in the Hope Valley, Derbyshire, England