S1, S01, S.I, S-1, S.1, Š-1 or S 1 may refer to:

Biology and chemistry

* S1 nuclease, an enzyme that digests singled-stranded DNA and RNA * S1: Keep locked up, a safety phrase in chemistry * Primary somatosensory cortex, also known as S1 * Tegafur/gimeracil/oteracil, also known as S-1, a chemotherapy medication

Entertainment

* S1 (Indian TV channel), a Hindi-language channel * S1 (Swiss TV channel), a German-language channel * S1 (producer), a hip hop producer, member of the group Strange Fruit Project * S1 No. 1 Style, a Japanese adult video company * Gibson S-1, a guitar made by the Gibson Guitar Corporation * A member of the S1W (group) that later became part of the music group Public Enemy.

Government

* Bill S-1, a pro forma bill in Canadian Parliament * Form S-1, a U.S. Securities and Exchange Commission filing * S-1 Executive Committee, a United States government entity during World War II * S1 (military), an administrative position within military units

Technology

* ACPI S1 power state, in computing; see * Apple S1, integrated computer used in the Apple Watch * Canon PowerShot S1 IS, a 2004 3.2 megapixel digital camera * FinePix S1 Pro, a 2000 interchangeable lens digital single-lens reflex camera by Fujifilm * Nikon Coolpix S1, a digital camera * S1 Corporation, an American software development company * S1 Core, a microprocessor-core * S1 MP3 Player * Samsung Galaxy S (2010 smartphone) * Sendo S1, a Sendo mobile phone model * Siemens S1, a Siemens mobile phone * Sony BDP-S1, a first generation Blu-ray Disc (BD) Player * S1, an Evolved Packet Core, EPC in an LTE/4G network

Transportation

Routes

China

* Line S1 (Beijing Subway) * Line S1 (Nanjing Metro) * Line S1 (Wenzhou Rail Transit) * S1 Yingbin Expressway in Shanghai

Germany

* S1 (Berlin), an S-Bahn line * S1 (Dresden), an S-Bahn line * S1 (Munich), an S-Bahn line * S1 (Nuremberg), an S-Bahn line * S1 (Rhine-Main S-Bahn), an S-Bahn line * S1 (Rhine-Ruhr S-Bahn), an S-Bahn line * S1 (Stuttgart), an S-Bahn line * a planned Bremen S-Bahn line * a Hamburg S-Bahn line * a Hanover S-Bahn line * a RheinNeckar S-Bahn line * a Rostock S-Bahn line * a Stadtbahn Karlsruhe line

Switzerland

* S1 (Bern S-Bahn), an S-Bahn line in the canton of Bern * S1 (RER Vaud), an S-Bahn line in the canton of Vaud * S1 (St. Gallen S-Bahn), an S-Bahn line in the canton of St. Gallen * S1 (ZVV), now subsumed by S24, a Zürich S-Bahn line

United States

* County Route S1 (California) * S1 (Long Island bus)

Other countries

* S1 (Vienna), an S-Bahn line in Austria * Line S1 (Milan suburban railway service), Italy * S-1 Strategic Highway, Pakistan * Expressway S1 (Poland) * FGC line S1, a suburban train line in Barcelona Province, Spain * Stagecoach Gold bus route S1, in Oxfordshire, England, UK

Vehicles

Aircraft

* Blackburn Buccaneer S.1 jet naval strike aircraft * Focke-Wulf S 1, a German Template:Focke-Wulf aircraft, Focke-Wulf aircraft * Fokker S.I, a 1919 Dutch primary trainer aircraft * Hopfner S-1, a Template:Hopfner aircraft, Hopfner aircraft * Letov S-1, a 1920 Czechoslovak surveillance aircraft * Loening S-1, a United States Army Air Service seaplane * Loughead S-1 Sport 1920 US biplane * Martinsyde S.1, a 1914 British biplane aircraft * Pantsir-S1, a Russian anti-aircraft system * Pitts S-1 aerobatic biplane * S-1 Loening, a United States Army Air Service seaplane * SSBS S1, a French experimental rocket * Swift S-1, a 1991 Polish single seat aerobatic glider

Cars

* Audi S1, performance variant of Audi A1 * Invicta S1, a 2004 sports car * S1 Scout Car, an armoured car built in Australia during the Second World War * Superformance S1 Roadster, a Lotus Seven Type replicar produced in South Africa 2001–2004

Other vehicles

* Alco S-1, a locomotive * PRR S1, a duplex locomotive developed by the Pennsylvania Railroad * USS S-1 (SS-105), a 1918 United States Navy experimental submarine

Other uses

* S1 (classification), a disability swimming classification * S postcode area covering Sheffield City Centre * in human anatomy: :* the first Sacral vertebrae, sacral vertebra :* the sacral spinal nerve 1 of the vertebral column :* the primary somatosensory cortex in the brain * ''Senior 1'', the First Year in the Scottish secondary education system * Season (television) or series one * Comet Ikeya-Seki, ''C/1965 S1'' * Upplands regemente (signal), a 1902 Signal Regiment of the Swedish Armed Forces

With superscripts and subscripts

S₁ may refer to : * S1 (heart sound), a heart sound in cardiac auscultation S¹ may refer to : * Circle, S¹, the n-sphere in two dimensions i.e. a circle * Inverse second (s⁻¹), a unit of frequency

S01

S01 may refer to : * Akai S01, an :Akai synthesizers, Akai synthesizer * ATC code S01 ''Ophthalmologicals'', a subgroup of the Anatomical Therapeutic Chemical Classification System * HMS Porpoise (S01), a 1956 Porpoise-class submarine of the Royal Navy * MULTI-S01, an encryption algorithm based on a pseudorandom number generator {{Letter-Number Combination Disambiguation