AT

AT may mean:
*Aarne-Thompson classification system
*AT Field, a force field in the anime Neon Genesis Evangelion
*Acceptance test
*Air Trecks, fictional inline skates in the manga and anime Air Gear
*Alimentary tract
*Atmel Corporation
*Anaerobic threshold
*"Análisis Transaccional" (Spanish "Transactional analysis"), a psychological method
*Anguilla, a World Meteorological Organization country code
*Anti-tamper, resistance to of a product, package, or system
*Anti-tank weapons
*Counter-terrorism, also known as "anti-terrorism" (AT)
*Appalachian Trail
*Aphex Twin
*Appropriate Technology
*Ashmore and Cartier Islands (FIPS 10-4 territory code and obsolete NATO country code
*Assistive technology
*IBM Personal Computer/AT
**AT form factor for motherboards and computer cases
** The common name for the 5-pin DIN keyboard connector
*Ataxia telangiectasia, an immunodeficiency disorder
*Atchison County, Kansas (county code)
*Attack Team (game), a 2000 computer game
*Audit trail
*Austria's ISO, 2-letter country code
**.at is the Internet country code top-level domain for Austria
*Automatic transmission
*Hayes command set for computer modems (all commands begin with the characters "AT")
*Royal Air Maroc (IATA airline designator)
*Abel Tasman, a seventeenth century Dutch explorer and merchant

At may mean:
*Ampere-turn (symbol), an International System of Units (MKS) unit of magneto-motive force
*Astatine, the chemical symbol for the element
*a subdivision equal to 1/100 of a Kip, the unit of currency in Laos

aT may mean:
*attotesla, an SI unit of magnetic flux density

at may mean:
* "@", the punctuation symbol now typically used in e-mail addresses
*at (Unix), to schedule tasks to be performed at a later date
*technical atmosphere (symbol), physical unit of pressure