SL

SL may refer to:

Arts and entertainment

 * SL (rapper), a rapper from London
 * Second Life, a multi-user 3D virtual world
 * Sensei's Library, an Internet site dedicated to the game of Go
 * Subdominant leittonwechselklänge
 * Leica SL, a mirrorless system camera by Leica Camera AG

Business and organizations

 * Sociedad Limitada, the Spanish version of a private limited company

Politics

 * Serbian Left (Srpska levica), a political party in Serbia
 * Stronnictwo Ludowe, a defunct Polish political party
 * Soyons Libres, a French political party

Transportation and vehicles

 * SL Corporation, a Korean auto parts company
 * Rio Sul Serviços Aéreos Regionais (IATA code SL), a Brazilian airline
 * Salt Lake City Southern Railroad (reporting mark SL)
 * Stor-Oslo Lokaltrafikk, a public transport operator in Akershus, Norway
 * Storstockholms Lokaltrafik, the public transport operator in Stockholm, Sweden
 * Thai Lion Air (IATA airline code SL)
 * Mercedes-Benz SL-Class, an automobile

Trade unions

 * Association of Social Educators, a trade union in Denmark

Geography

 * Sierra Leone, in West Africa, ISO 3166 code
 * Saarland, a state of Germany
 * SL postcode area of the United Kingdom
 * Sungai Long, in Selangor, Malaysia
 * Sri Lanka, an island country in South Asia

Language

 * Sl (digraph), a Latin-script digraph
 * Sign language, used by deaf persons
 * Slovene language (ISO 639-1 code "sl")

Biology

 * Sensu lato, a term used in taxonomy to mean "in the wider sense" of a definition
 * Standard length, a common measurement for fish
 * Abbreviation for × Sophrolaelia, an orchid genus

Computing

 * sl, a humorous command in some Unix-based systems that draws an animation of a steam locomotive, intended to be invoked as a typo of ls
 * .sl, the country code top-level domain for Sierra Leone
 * SL (complexity), a class of computational complexity
 * Scientific Linux, a Linux distribution
 * Service Loading, a variant of WAP push method

Mathematics

 * SL (complexity), a class of computational complexity
 * sl (elliptic function), sine lemniscate function
 * Special linear group in mathematics, denoted SLn
 * Special linear Lie algebra, denoted $$\mathfrak{sl}_n(F)$$ or $$\mathfrak{sl}(n, F)$$.

Other uses

 * Serjeant-at-law, a former type of barrister in England and Ireland
 * Sine loco in bibliographies means that place of publication is unknown
 * Surround Left (SL) speaker on a 5.1 surround sound setup