| Acronym | Definition |
|---|
| ATAC | Air Transport Association of Canada |
| ATAC | Advanced Tactical |
| ATAC | Agenzia Per I Trasporti autoferrotranviari del Comune Di Roma |
| ATAC | American Teens Against Crime (Hardy Boys Undercover Brothers book series) |
| ATAC | Advanced Traceability And Control |
| ATAC | Advanced Team Attack Control (Counter-Strike gaming plugin) |
| ATAC | Advanced Tactical Air Command |
| ATAC | Australian Transport Advisory Council |
| ATAC | Air Transportation Association of Canada |
| ATAC | Association of Theatrical Artists and Craftspeople (Bloomfield, NJ) |
| ATAC | Advanced Tactics Airsoft Class (Albany, OR) |
| ATAC | Antiterrorist Alert Center |
| ATAC | Automatic Targeting Attack Communicator (from the movie For Your Eyes Only) |
| ATAC | Anti-Terrorism Advisory Committee |
| ATAC | Azienda Tramvie e Autobus del Comune Di Roma |
| ATAC | Asociación Tecnológica Amateur de Comunicaciones |
| ATAC | Advanced Technology Advisory Committee |
| ATAC | Art Talks Artists' Collective |
| ATAC | Association Technique pour l'Action Culturelle (French: Technical Association for Cultural Action) |
| ATAC | Association Terre d'Aragon en Cabardès (French: Land Association of Aragon Cabardès; Aragon, France) |
| ATAC | Avaya Technology and Consulting |
| ATAC | Aerospace Technology Advisory Committee |
| ATAC | Adaptive Transform Acoustic Coding (more commonly seen as ATRAC) |
| ATAC | AIDS Treatment Action Coalition |
| ATAC | Anti Terrorism Alert Center (US) |
| ATAC | Advanced Technology Assessment Center |
| ATAC | Army Tank-Automotive Center (US Army; predecessor to TACOM) |
| ATAC | Arizona Transfer Articulation Committee (Phoenix, AZ) |
| ATAC | antiterrorism alert center (Navy) (US DoD) |
| ATAC | Air Transportable Acoustic Communication |
| ATAC | Air-Transportable Acoustic Communication |
| ATAC | Air Tasking Authority Commander |
| ATAC | Acquisition Transformation Action Council |
| ATAC | Apparel Textile Action Committee (Canada) |
| ATAC | Advanced Technical Assistance Center |
| ATAC | Advanced Tactical Assault Command (gaming group) |
| ATAC | (acrylamidopropyl)trimethylammonium Chloride |
| ATAC | Advanced Tactics and Countermeasures |
| ATAC | Asset Tracking and Accountability Control System |
| ATAC | Airborne Tactical Air Coordinator |
| ATAC | Aegis Tactical Assessment Capability |
| ATAC | All Terrain Articulated Crane |
| ATAC | Atrial Tachycardia (medical) |
| ATAC | Anti-Terrorism Advisory Council |
| ATAC | Arimidex, Tamoxifen Alone or in Combination (cancer study) |
| ATAC | Area Tallahassee Aquatic Club (Florida) |