ST

ST or St may refer to:

In geography:

• São Tomé and Príncipe, ISO 3166-1 country code

In technology:

• .st, Internet country code top-level domain for São Tomé and Príncipe
• ST connector, a type of optical fiber connector
• Atari ST, a personal computer
• Internet Stream Protocol, an experimental Internet protocol
• Spread Tow, a technology for spreading a tow to make ultra light fabric for the composites industry
• State Threads, a user-space threading C-library, especially for network-applications
• Structured Text, a high-level programming language that syntactically resembles Pascal

In businesses and organizations:

• St or StA are short for Stammaktie meaning Common stock (US) or ordinary shares (British), on the German stock exchanges.
• STMicroelectronics, a worldwide manufacturer of semiconductors
• Secret Team, an alleged covert alliance between the CIA and American industry
• Sound Transit, the popular name of Washington state's Central Puget Sound Regional Transit Authority
• Springfield Terminal Railway (Vermont), a subsidiary of Pan Am Railways, reporting mark ST
• Statstjänstemannaförbundet, or Swedish Union of Civil Servants, a trade union
• Student Transportation, Inc., a school bus contractor
• Suffolk County Transit, or Suffolk Transit, the bus system serving Suffolk County, New York
• Germania (airline) IATA airline designator

In science:

• String theory, a branch of theoretical physics
• Stanton number, a term used in physics
• Strouhal number, a term used in fluid mechanics
• s.t. an abbreviation for "such that"

In other uses:

• an abbreviation commonly used for Maharashtra State Road Transport Corporation
• St, a contraction of Saint, especially in Christianity (female Ste)
• St, a contraction of Street
• School Tycoon, a video game
• Self-titled, a term used in the record industry for eponymous albums
• Sesotho language ISO language code
• Standard part function, a term used in non-standard analysis
• Star Trek, a television and film franchise
• Stone (weight), a unit of mass used in the British Isles and other countries
• Stormtrack, an early magazine about storm chasing
• Street, a public thoroughfare
• the city of Split, Croatia, license plate code and common abbreviation
• Suicidal Tendencies, an American heavy metal/hardcore punk band
• The Legend of Zelda: Spirit Tracks, a video game
• a part of many abbreviations of ordinal numbers, such as 1st and 4th