AAT or Aat may refer to:
Biochemistry Alpha 1-antitrypsin, also α1-antitrypsin (A1AT), a glycoprotein Aspartate transaminase, or aspartate aminotransferase, an enzyme AAT, a codon for the amino acid asparagine
Places Transport infrastructure Achanalt railway station Asia Airfreight Terminal, Hong Kong International Airport Altay Xuedu Airport in Xinjiang Region, China (IATA airport code AAT) Alturas Municipal Airport, California, US (Location identifier AAT)
Other places Ath, Belgium (Dutch: ) Australian Antarctic Territory AutoAlliance Thailand, a joint venture automobile manufacturing plant
Science and technology Anglo-Australian Telescope Animal-assisted therapy Apple Advanced Typography, a font rendering technology Aquatic Ape Theory, a theory in human evolution Ancient astronauts, or ancient astronaut theory
Other uses Aat (queen), an ancient Egyptian queen consort of the 12th dynasty Administrative Appeals Tribunal, in Australia And Another Thing (disambiguation) Art & Architecture Thesaurus, a controlled vocabulary used for describing items of art Association of Accounting Technicians, a professional member body Arvanitika, a variety of Albanian spoken in Greece The Bible, An American Translation Armored Assault Tank, a Separatist tank in the prequel era of the Star Wars universe Hong Kong Academic Aptitude Test, a standardized examination from 1978 to 2000
See also A80 (disambiguation)