S9 may refer to:
Transportation SIAI S.9, a 1918 Italian flying boat Aircraft registration prefix of São Tomé and Príncipe USS S-9 (SS-114), a 1920 S-class submarine of the United States Navy County Route S9 (California) Rans S-9 Chaos, a light aerobatic aircraft East African Safari Air's IATA code
Rail S9 (Berlin), an S-Bahn line in Germany S9 (Milan suburban railway service) in Italy S9 (RER Vaud), an S-Bahn line in Switzerland S9 (Rhine-Ruhr S-Bahn) line in Germany S9 (Rhine-Main S-Bahn) line in Germany S9 (St. Gallen S-Bahn), a line in the canton of St. Gallen, Switzerland S9 (ZVV), a Zurich S-Bahn line in the cantons of Zurich and Schaffhausen, Switzerland S9, a Basel S-Bahn line in the cantons of Basel-Landschaft and Solothurn, Switzerland S9, a Karlsruhe Stadtbahn line, Germany S9, a Lucerne S-Bahn line in the cantons of Aargau and Lucerne, Switzerland S9, a Styria S-Bahn line in Austria Line S9 (Nanjing Metro), China Prussian S 9, a 1908 German steam-locomotive class Sri Lanka Railways S9, a diesel multiple-unit train
Other uses Samsung Galaxy S9, a smartphone by Samsung Samsung Galaxy Tab S9, a series of high-end Android tablets by Samsung S9 (classification), a disability swimming classification S 9 (Abydos), an Ancient Egyptian tomb in Abydos, possibly that of pharaoh Neferhotep I S9: Keep container in a well-ventilated place, a safety protocol S9 fraction, a postmitochondrial liver fraction Cowon S9, a portable media player British NVC community S9, a swamps and tall-herb fens community in the British National Vegetation Classification system Motorola S9, a Motorola product S9, a district of the S postcode area in Sheffield, England S9, a termination record in Motorola's SREC (file format) S9, an allotrope of sulfur
See also S09, a quantum key distribution protocol HMS Oberon (S09), a 1961 British Royal Navy Oberon-class submarine Brave Fire S09, an Osamu Tezuka anime 9S (disambiguation)