ATG may refer to:
Companies ATG Stores, an e-tail site Advanced Technology Group (Apple), a former division of Apple Computer Advanced Technology Group (Novell), a former division of Novell Aviation Technology Group, the defunct developer of the Javelin Very Light Jet (VLJ) Auction Technology Group, a digital marketplace company formerly known as ATG Media
Military Alaska Territorial Guard, a military reserve force in World War II Anti-tank gun, a mobile weapon used in Anti-tank warfare
Organizations Alternative Tourism Group, a Palestinian NGO Ambassador Theatre Group, a theatre group in the UK
Science ATG, a three-base sequence of DNA in the genetic code representing a start codon and/or methionine Anti-thymocyte globulin, antibodies to prevent and treat transplant rejection ATG is short for "autophagy-related", which can apply to either genes or proteins
Other uses Ankara Tren Garı, a mixed use building in Ankara, Turkey Anti Tank Guitar, a string instrument Art Technology Group, a software developer Art Theatre Guild, a Japanese film production company Auto-gating, in night vision devices Automatic Tank Gauging The ISO 3166 code for Antigua and Barbuda, a country in the east Caribbean Sea