ATT may refer to:
Telecommunications and computing AT&T (disambiguation) AT&T Inc., an American telecommunications company founded 1983 (formerly Southwestern Bell or SBC Communications) AT&T Corporation, the original AT&T founded 1885 (formerly American Telephone & Telegraph), purchased by SBC in 2005 AT&T Mobility, a subsidiary of AT&T Inc. for wireless services AT&T Mexico, an international wireless subsidiary of AT&T Inc ATI Tray Tools - freeware program developed by Ray Adams for ATI Radeon video cards
Transportation and government Attitude, in dynamics (aircraft attitude) Aircraft Transport and Travel, a 1910s British airline Atmautluak Airport, an airport in Alaska (IATA: ATT) Attadale railway station, United Kingdom (National Rail code) American Tobacco Trail Authorization to transport, a permit issued in Canada to transport Restricted and Prohibited firearms Arms Trade Treaty, a 2014 multilateral treaty to control the illicit trade of conventional weapons Amadou Toumani Touré, president of Mali
Legal professionals Attorney at law Association of Taxation Technicians, a United Kingdom professional association
Biology Attachment, the binding of a virus to its target cell ATT, a codon for the amino acid isoleucine
Music A.T.T., a British dance music act Hamdan ATT (1946–2025), Indonesian dangdut singer
Other uses Academy Transformation Trust, a multi-academy trust in England American Top Team, a mixed martial arts team based in Coconut Creek, Florida