S is the nineteenth letter of the English alphabet. S may also refer to:

History

* an Anglo-Saxon charter's number in Peter Sawyer (historian), Peter Sawyer's, catalogue

Language and linguistics

* Long s (ſ), a form of the lower-case letter s formerly used where "s" occurred in the middle or at the beginning of a word * -s, a suffix added to some English surnames, originally meaning "son of" * , the International Phonetic Alphabet symbol for a voiceless alveolar sibilant sound * S, the Subject (grammar), subject of an intransitive verb

Mathematics and logic

* Integral symbol (∫), used in mathematics to denote integrals and antiderivatives * S combinator in combinatory logic * Sphere * ''s(n)'', the aliquot sum of an integer n

Physics and chemistry

* Sulfur, symbol S, a chemical element * S, the symbol for entropy * S, a non-SI unit used to designate molecule size named after the Svedberg sedimentation coefficient * ''S'', a label that denotes one of two chiral center configurations in the Chirality_(chemistry)#Stereogenic centers, ''R''/''S'' system * ''s'', one of the Mandelstam variables, the square of the invariant mass * Siemens (unit), the SI derived unit of electric conductance * S-block of the periodic table, which includes alkali metals, alkaline earth metals, and hydrogen and helium * Spin (physics) * s, an abbreviation for solid

Biology and medicine

* Serine, a standard amino acid abbreviation * ATC code S ''Sensory organs'', a section of the Anatomical Therapeutic Chemical Classification System * S phase or synthesis phase, a period in the cell cycle during interphase

Computing

* Samsung Galaxy S (2010 smartphone), the first flagship smartphone of the Samsung Galaxy S series * S (programming language), an environment for statistical computing and graphics * <s>, the opening tag for the HTML element denoting information that is "no longer accurate or no longer relevant", usually rendered as ~~strike-through text~~

People

* ''S'', the pen name of Percy Bysshe Shelley * "S.", the nickname for Solomon Shereshevsky (1886-1958), a Russian journalist, mnemonist, and synesthete notable for his unusual memory abilities

Arts and entertainment

Books

* S. (Dorst novel), ''S.'' (Dorst novel), written by Doug Dorst based on story by J.J. Abrams * S. (Updike novel), ''S.'' (Updike novel), part of the John Updike bibliography, Scarlet Letter trilogy by John Updike * S (novel series), ''S'' (novel series), a 2005-2006 light novel series * ''"S" Is for Silence'', the nineteenth novel in Sue Grafton's "Alphabet mystery" series, published in 2005

Music

* S, the stage name of singer-songwriter and guitarist Jenn Champion * S (group), a short-lived South Korean music group active in 2003 and 2014 * S (EP), ''S'' (EP), a 2001 EP by Japanese musical duo NaNa * Numbering of List of compositions by Franz Liszt, Franz Liszt's works according to Humphrey Searle's catalogue

Television

*S, the production code for the 1965 ''Doctor Who'' serial ''The Time Meddler''

Comics

* S, the protagonist of ''Heavy Liquid (comics), Heavy Liquid''

Automobiles

Production models

* Aion S, a Chinese electric compact executive sedan * Jaguar S-Type (1963), a British sports saloon * Jaguar S-Type (1999), a British executive saloon * Mercedes-Benz S-Class, a German full-size luxury car series * Mini Cooper S, a British hot hatch * Neta S, a Chinese electric sedan * Tesla Model S, an American electric executive sedan

Prototypes and concepts

* Sony Vision-S, Japanese mid-size electric concept sedan

Series and trims

* Acura Type-S, a range of Japanese performance vehicles * Audi S, a range of German performance vehicles * Honda S series, series of Japanese sports cars * Jaguar S, a range of British performance vehicles

Other uses

* Safety (gridiron football position) * South on a map or compass, one of the four cardinal directions * s, the SI symbol for second * Shilling (British coin) * S postcode area, a postcode area including Sheffield, England * A party label for the Swedish Social Democratic Party * Strike (baseball) * S band, a band of radio which ranges from 2 to 4 GHz * List of military time zones#S, Sierra, the military time zone code for UTC−06:00 * Cool S, a graffiti sign