| Acronym | Definition |
|---|
| ATR | Attribute |
| ATR | Americans for Tax Reform |
| ATR | Average True Range (financial indicator) |
| ATR | Attenuated Total Reflectance |
| ATR | Automatic Target Recognition |
| ATR | Automatic Traffic Recorder |
| ATR | All That Remains (band) |
| ATR | Attenuated Total Reflection |
| ATR | Avions de Transport Regional (turboprop aircrafts) |
| ATR | Action Taken Report |
| ATR | Atari Teenage Riot (band) |
| ATR | Answer to Reset |
| ATR | Advanced Test Reactor |
| ATR | Ataxia Telangiectasia and Rad3-related |
| ATR | Advanced Telecommunications Research Institute International |
| ATR | Registered Art Therapist |
| ATR | Air Transport Rack |
| ATR | Above the Rest |
| ATR | Advanced Tongue Root (phonetics) |
| ATR | Above the Rim (Reebok) |
| ATR | Anti-Tank Rifle |
| ATR | All Terrain Racing |
| ATR | Art Therapist Registered (Art Therapy Credentials Board) |
| ATR | Audio Tape Recorder |
| ATR | Aided Target Recognition |
| ATR | Automatic Terminal Recognition |
| ATR | A Territory Resource |
| ATR | Alliance for Transportation Research |
| ATR | Analog Tape Recorder |
| ATR | Accord Type R (Honda Europe) |
| ATR | Achilles Tendon Rupture |
| ATR | Acceptance Test Report |
| ATR | Action for Tinnitus Research |
| ATR | Autonomous Target Recognition |
| ATR | Air Turbo Ramjet |
| ATR | Authorization to Return |
| ATR | Apollo Token Ring |
| ATR | Alaska Trauma Registry |
| ATR | Alternate Trunk Routing |
| ATR | Air Turbo Rocket |
| ATR | Arizona Trail Riders (Motorcyclists) |
| ATR | Against-The-Rule Astigmatism |
| ATR | Above Top of Rail |
| ATR | Acceptance Test Review |
| ATR | American Technology Research, Inc |
| ATR | All Thread Rod |
| ATR | Air Transport Rating |
| ATR | Austin Trumbull Radio (ARINC) |
| ATR | Advanced Tactical Radar |
| ATR | Air Traffic Requirements |
| ATR | Ambient Temperature Recorder |
| ATR | As They Rise (kiln-fired brick; UK) |
| ATR | Ammunition Transaction Report |
| ATR | Authority to Recruit |
| ATR | Air Traffic Regulations |
| ATR | attrition reserve (US DoD) |
| ATR | Antitransmit Receive |
| ATR | All Terminal Reliability |
| ATR | Awareness, Trial, Repeat |
| ATR | Agency Technical Representative |
| ATR | Answering Time Recorder |
| ATR | Advice to Receive (electronic payment processing) |
| ATR | Available to Reserve (manufacturing) |
| ATR | Assistant Technical Representative |
| ATR | Approved Tank Requirements |
| ATR | Agency Telecommunications Representative |
| ATR | Automatic Trouble Reporting |
| ATR | Admission Temporaire Roulette (Customs Documentation, Turkey) |
| ATR | Augmented Tree-Based Routing |
| ATR | Applied Tariff Rate |
| ATR | Australian Technology Resources |
| ATR | Airline Transport Rack |
| ATR | Agency Telecommunications Request |
| ATR | Above Threshold Reporting |
| ATR | Annual Technology Report |
| ATR | Acceptance of TEMPEST Risk |
| ATR | Aviation Transport Rack |
| ATR | Aerial Target Review |
| ATR | Anti-Theft Request (signal) |
| ATR | Automated Transaction Report |
| ATR | Anti-Time Reaction (Star Trek) |
| ATR | Authorized Traffic Request |
| ATR | Air Transit Route |
| ATR | Alltech Recycling, Inc (Fort Worth, TX) |