S38

S38 may refer to:
 * BMW S38, an automobile engine
 * S38: In case of insufficient ventilation wear suitable respiratory equipment, a safety phrase
 * Short S.38, a British biplane
 * Sikorsky S-38, a 1928 American amphibious sesquiplane
 * Sulfur-38, an isotope of sulfur
 * USS S-38 (SS-143), a submarine of the United States Navy