ST
ST, St, or St. may refer to:

Arts and entertainment
Stanza, in poetry
Suicidal Tendencies, an American heavy metal/hardcore punk band
Star Trek, a science-fiction media franchise
Summa Theologica, a compendium of Catholic philosophy and theology by St. Thomas Aquinas
St or St., abbreviation of "State", especially in the name of a college or university

Businesses and organizations
Transportation
Germania (airline) (IATA airline designator ST)
Maharashtra State Road Transport Corporation, abbreviated as State Transport
Sound Transit, Central Puget Sound Regional Transit Authority, Washington state, US
Springfield Terminal Railway (Vermont) (railroad reporting mark ST)
Suffolk County Transit, or Suffolk Transit, the bus system serving Suffolk County, New York

Other businesses and organizations
Statstjänstemannaförbundet, or Swedish Union of Civil Servants, a trade union
STMicroelectronics, a worldwide manufacturer of semiconductors

Geography
São Tomé and Príncipe (ISO 3166-1 country code ST)
.st, Internet country code top-level domain for São Tomé and Príncipe
Saxony-Anhalt, a state of Germany
Split, Croatia (vehicle plate code ST)
Stoke-on-Trent postcode area, United Kingdom
St or St., abbreviation of Saint
St or St., abbreviation of Street
St or St., abbreviation of Strait

Language and typography
Sesotho language (ISO 639-1 language code "st")
ﬅ, or st, a typographic ligature
Standard Theory in generative grammar

Science and technology
Computing
ST connector, a type of optical fiber connector
Atari ST, a personal computer
Prefix of hard disk drives made by Seagate Technology, e.g. ST-506
Internet Stream Protocol, an experimental Internet protocol
Structured text, a high-level programming language that syntactically resembles Pascal and is designed for programmable logic controllers (PLC)
.st, the Internet country code top-level domain (ccTLD) for São Tomé and Príncipe
St (terminal emulator), minimalist terminal emulator by suckless.org

Mathematics
Standard part function, a term used in non-standard analysis

Physics
Stanton number St, used in physics
Strouhal number St, used in fluid mechanics
String theory

Units of measurement
Stokes (unit) (St), a CGS unit of kinematic viscosity
Stone (weight) (st.), a unit of mass used in the British Isles and other countries

Medicine
ST segment, the part of an electrocardiogram connecting the QRS complex and the T wave
Sulfotransferase, enzymes that catalyze the transfer of a sulfo group
Heat-stable enterotoxin, secretory peptides produced by some bacterial strains, such as enterotoxigenic Escherichia coli

Other uses
-st, a suffix for an ordinal number, such as 1st or 21st
Saint (St or St.), especially in Christianity
Scheduled Tribes, in India
Ship prefix for a steam tug
Sine tempore (s.t.), Latin term indicating that a lecture will begin at the exact time; see Academic quarter (class timing)
Striker (association football), a position in association football
ST, a type of London bus

See also
STST (disambiguation)
STFC (disambiguation) for uses of ST F.C.