S15 may refer to:
Aircraft Sikorsky S-15, a prototype Russian biplane floatplane Spalinger S.15, a Swiss glider Stemme ASP S15, a German sailplane
Automobiles GMC Jimmy (S-15), a SUV Laffly S15, a family of French all-terrain military vehicles Nissan Silvia (S15), a sports car
Rail and transit Lines S15 (ZVV), an S-Bahn line in Zurich, Switzerland S15, a line of St. Gallen S-Bahn operating over the Frauenfeld–Wil railway in Switzerland S15 (Berlin), planned line on S21 rail project
Locomotives LSWR S15 class, a British steam locomotive
Stations Hataki Station, in Ōzu, Ehime Prefecture, Japan Ikawadani Station, in Nishi-ku, Kobe, Hyōgo Prefecture, Japan Ojima Station, in Kōtō, Tokyo, Japan Otaru Station, in Otaru, Hokkaido, Japan Sakuragawa Station (Osaka), in Naniwa-ku, Osaka, Japan Sakura-hommachi Station, in Minami-ku, Nagoya, Aichi, Japan
Science 40S ribosomal protein S15 British NVC community S15, a swamps and tall-herb fens community in the British National Vegetation Classification system Explorer 11, a NASA satellite Ribosomal S15 leader S15: Keep away from heat, a safety phrase
Vessels
, a submarine of the Royal Navy , a torpedo boat of the Imperial German Navy , a submarine of the United States Navy
Other uses S15 (classification), a disability swimming classification County Route S15 (California)