S11 may refer to:
Aircraft Fokker S-11, a trainer aircraft Rans S-11 Pursuit, an American light aircraft SABCA S.11, a Belgian prototype airliner Sikorsky S-11, a Russian reconnaissance aircraft SPAD S.XI, a French reconnaissance biplane
Rail and transit Lines S11 (Cologne S-Bahn), Germany S11 (ZVV), Zürich, Switzerland Line S11 (Chengdu Metro), China Line S11 (Milan suburban railway service), Italy S11, of the Breisgau S-Bahn, Germany S11, of the Hamburg S-Bahn, Germany S11, of the Karlsruhe Stadtbahn, Germany
Locomotives ALCO S-11, a diesel-electric switcher LSWR S11 class, a steam locomotive Sri Lanka Railways S11, a diesel multiple unit
Stations Kitanada Station, in Ōzu, Ehime Prefecture, Japan Morishita Station (Tokyo), in Kōtō, Tokyo, Japan Myōhōji Station (Hyōgo), in Suma-ku, Kobe, Hyōgo Prefecture, Japan Sakurayama Station, in Mizuho-ku, Nagoya, Aichi Prefecture, Japan Wutthakat BTS station, in Bangkok, Thailand Zenibako Station, in Otaru, Hokkaido, Japan
Roads S11 highway (Georgia) Expressway S11 (Poland) County Route S11 (California), United States
Submarines Brazilian submarine Rio Grande do Sul (S11) (Balao class), in service 1963–1972 Brazilian submarine Rio Grande do Sul (S11) (Tench class), in service 1972–1978 , of the Royal Navy , of the United States Navy
Other uses S11 (classification), a disability swimming classification S11 (protest), at the meeting of the World Economic Forum in Melbourne, Australia on September 11, 2000 40S ribosomal protein S11 British NVC community S11, see swamps and tall-herb fens in the British National Vegetation Classification system Nissan Silvia (S11), a sports car Project S-11, a video game September 11 attacks , the first Scattering parameter in an electrical network. S11, a postcode district in Sheffield, England S-11, a creature in the Sharktopus film Voltage reflection coefficient of a two-port network