| Acronym | Definition |
|---|
| ATG | Art Technology Group, Inc (Cambridge, MA) |
| ATG | Antigua and Barbuda (ISO Country code) |
| ATG | AGL Resources (stock symbol) |
| ATG | Anti-Thymocyte Globulin |
| ATG | Advanced Technology Group |
| ATG | Afloat Training Group |
| ATG | Air to Ground |
| ATG | Automatic Tank Gauging |
| ATG | Air-To-Ground |
| ATG | At the Gates (band) |
| ATG | Alternative Tourism Group |
| ATG | Audit Techniques Guide |
| ATG | Alaska Territorial Guard |
| ATG | Alexander the Great |
| ATG | Allied Technology Group |
| ATG | Aviation Technology Group Inc |
| ATG | Address Translation Gateway |
| ATG | All Time Greatest |
| AtG | Andre the Giant (wrestler) |
| ATG | Antitank Gun |
| ATG | Accordionists and Teachers Guild (est. 1940) |
| ATG | Automatic Test Generator (I-Logix, Inc.) |
| ATG | amphibious task group (US DoD) |
| ATG | Antenna Transceiver Group |
| ATG | Ass to Grass (deep, low squat) |
| ATG | Advanced Training Group |
| ATG | Adelaide Theatre Guide (Adelaide, Australia) |
| ATG | Abbreviated Trouble History |
| ATG | Algebraic and Geometric Topology |
| ATG | Assign Trunk Group |
| ATG | Association Technique de l'Industrie du Gaz en France (French: Technical Association of the Gas Industry in France) |
| ATG | Aartselaars Toneel Gezelschap (Dutch: Aartselaar Theatre Company; Aartselaar, Belgium) |
| ATG | assign trunk group cluster (US DoD) |
| ATG | AFOATS Training Guide (USAF) |
| ATG | Aerospace Test Group |
| ATG | Advanced Transport Group |
| ATG | Antenna Test Group |
| ATG | American Transportation Group (Iselin, New Jersey) |
| ATG | Austin Tavern Guild |
| ATG | Afrikaanse Taalgenootskap (Afrikaans Language Association) |
| ATG | Afloat Tactical Group |
| ATG | Aktiebolaget Trav cch Galopp |
| ATG | Austauschgeraet (German: Exchange Unit) |
| ATG | Array Transition Group |
| ATG | Absolute Track Geometry |
| ATG | Automatic Target Generation |
| ATG | Arab Theatre Group (Montreal, QC, Canada) |
| ATG | Aysmmetric Twin Guide |
| ATG | Allied Tactical Guerillas (game) |
| ATG | A Touch of Glass (now Henigman Remodeling & Glass; Forsyth, GA) |
| ATG | Antiques Trade Gazette (art market; UK) |
| ATG | Adhesive Transfer Gun (various companies) |
| ATG | All Terrain Grade (Dell computer) |