# T (disambiguation)

T, or t, is the twentieth letter of the English alphabet.
T may also refer to:

## Codes and units

* T, Tera- as in one trillion
* T, the symbol for "True" in logic
* T, the usual symbol for period, the reciprocal of frequency
* T, the symbol for Tesla, the SI unit of magnetic field
* t, the SI symbol for tonne or metric ton
* t, the usual symbol for time
* t, the angular coordinate of the polar coordinate system (usually ϕ or θ) is sometimes denoted by t
* $\tau$, the symbol for torque
* ⊤, the top element of a partially ordered set
* T, short for tablespoon
* t, short for teaspoon

## Names

* Titus (praenomen), common name throughout Roman history, regularly abbreviated T

## Entertainment
### Literature

* T, a novel by Victor Pelevin
* T (magazine), a fashion magazine, full name T: The New York Times Style Magazine
* "T" Is for Trespass, the twentieth novel in Sue Grafton's "Alphabet mystery" series, published in 2007
* T-unit, a grammatical term

### Film and television

* Big T, ring name of American retired professional wrestler Ahmed Johnson (born 1963)
* Mr. T (born 1952), American television actor
* T, the production code for the 1965 Doctor Who serial Galaxy 4
* The T logo for the American Spanish-language network Telemundo
* T (2023 film), an Indian Odia-language film by Jitesh Kumar Parida

### Music

* Ice-T (born 1958), American rapper and actor
* T (Funker Vogt album), a 2000 aggrotech album by Funker Vogt
* T (TVXQ album), a 2008 TVXQ album
* T (Teflon Brothers album), a 2009 album by Finnish hip hop group Teflon Brothers
* "t," an Iamamiwhoami song
* T, abbreviation for tutti
* T, abbreviation for tenor
* t, note abbreviation in tonic sol-fa for seventh scale degree
* T-Babe, a virtual pop singer

### Video games

* T (teen), a game rating from the Entertainment Software Rating Board which the board believes is suitable for those aged 13 years and older

## Finance and business

* AT&T, an American phone company with the New York Stock Exchange ticker symbol T
* T-Mobile International AG, mobile network operator based in Germany
* T-Systems, German IT services company
* T-Online, German Internet Service Provider
* Treasury (as in T-Bill, T-Bond, T-Note)
* T, a mintmark for Nantes, France

## Science
### Biology and medicine

* Troponin T, one of the three troponins
* Haplogroup T (mtDNA), a human mitochondrial DNA (mtDNA) haplogroup
* T cells, part of the components of the immune system along with B cells
* T, the one-letter code used for threonine, one of the 20 amino acids used in transcription of a polypeptide chain
* Thymine, one of the four nucleic acids of DNA
* T, gene and protein symbol for the transcription factor brachyury
* Thoracic vertebrae T-1 through T-12
* T wave, the repolarization wave of cardiac ventricles in electrocardiography
* T, a common abbreviation for the male sex hormone testosterone

### Palaeontology

* T-rex, abbreviation for Tyrannosaurus rex

### Meteorology

* Thunderstorm
* T-number in the Dvorak technique, a way to rate storm intensity

### Physics and chemistry

* T, symbol for tritium, a radioactive isotope of hydrogen
* T-symmetry in particle physics
* Class T, a cool brown dwarf class of stars
* ΔT (disambiguation): a variety of meanings related to changes in a quantity denoted by T, such as time or temperature

### Mathematics

* T score, a statistical term
* Student's t-distribution, statistical term
* T, in modal logic
* $\mathbb {T} ^{n}$, the n-dimensional torus ($\mathbb {R} ^{n}/\mathbb {Z} ^{n}$)
* $\mathbb {T}$, the Circle group
* A$^T$, the transpose of a matrix A

## Technology and computing

* T (programming language), created in the early 1980s
* T, Toshiba's mobile phones in Japan
* T, an abbreviation for telephone number
* t, an abbreviation for microblogging service Twitter
* t-distributed stochastic neighbor embedding, a machine learning algorithm for data visualization
* T-pose, a default pose for a 3D model's skeleton before it is animated
* Landing T, a ground signal that indicates the wind direction in aerodromes
* Transfer (computing), in computer technology, a data transfer, often used to measure speed (e.g. megatransfers per second)

## Transportation
### Equipment

* Ford Model T, a motor car produced in the U.S. 1908–1927
* NZR T class steam locomotives in New Zealand
* OS T1000, an Oslo Metro train
* T gauge, a scale for model railroad trains
* Tank locomotive

### Public transport
#### Japan

* Tanimachi Line, a subway service operated by the Osaka Metro, labeled
* Tokyo Metro Tozai Line, a subway service operated by the Tokyo Metro, labeled
* Tsuyama Line, a railway service operated by West Japan Railway Company, with the official service symbol

#### United States

* Massachusetts Bay Transportation Authority (nicknamed the "T")
* Pittsburgh Light Rail, commonly called the T
* T (New York City Subway service)
* T Line (Sound Transit) in Tacoma, Washington
* T Third Street in San Francisco, California
* Trinity Metro, formerly known as "The T", a transit agency serving Fort Worth, Texas and suburbs

#### Other countries

* Oslo Metro or Oslo T-bane
* Stockholm Metro or T-bana

## Phonetics

* [t], the International Phonetic Alphabet character for the voiceless alveolar plosive
* [ʈ], the IPA character representing the voiceless retroflex stop

## Other uses

* "The T", a nickname for the rural part of Pennsylvania due to its shape when eliminating the Pittsburgh and Philadelphia Metropolitan Areas, also known by its slang term Pennsyltucky
* Т, a letter of the Cyrillic alphabet
* T-bone steak, the cut of meat
* T-shirt, a type of clothing
* T in the Park, an annual music festival, held in Kinross, Scotland and named after its main sponsor, the brewing company Tennents
* Crossing the T, a classic naval warfare tactic
* Stealing the 'T', an historic college prank as the "T" is stolen from the Tech Tower at the Georgia Institute of Technology
* T (Tango), the military time zone code for UTC−07:00