S39

S39 may refer to:

Aviation

 * Blériot-SPAD S.39, a French reconnaissance aircraft
 * Letov Š-39, a Czechoslovakian sport aircraft
 * Prineville Airport, in Crook County, Oregon, United States
 * Sikorsky S-39, an American flying boat

Other uses

 * S39: Wear eye/face protection, a safety phrase
 * New Jersey Route 68, designated Route S39 until 1953
 * Sulfur-39, an isotope of sulfur
 * USS S-39 (SS-144), a submarine in the United States Navy