- A – analog
- A1C – Airman 1st Class (USAF E-3)
- A2C2 – Army airspace command and control
- A-3 – (Operations Directorate (COMAFFOR))
- A-5 – (Plans Directorate (COMAFFOR))
- AA – Anti-aircraft
- AA – assembly area
- AA – assessment agent
- AA – avenue of approach
- AAA – antiaircraft artillery
- AAA – arrival and assembly area
- AAA – assign alternate area
- AAAS – amphibious aviation assault ship
- AABB – American Association of Blood Banks
- AABWS – amphibious assault bulk water system
- AAC – activity address code
- AAC – Army Air Corps (British)
- AAC – Australian Army Cadets (Australia)
- AACG – arrival airfield control group
- AADC – area air defense commander
- AADP – area air defense plan
- AA&E – arms, ammunition, and explosives
- AAEC – aeromedical evacuation control team
- AAFC – Australian Air Force Cadets (Australia)
- AAFES – Army and Air Force Exchange Service
- AAFIF – automated air facility information file
- AAFS – amphibious assault fuel system
- AAFSF – amphibious assault fuel supply facility
- AAGS – Army air-ground system
- AAI – air-to-air interface
- AAM – air-to-air missile
- AAMDC – US Army Air and Missile Defense Command
- AAOE – arrival and assembly operations element
- AAOG – arrival and assembly operations group
- AAP – Allied administrative publication
- AAP – assign alternate parent
- AAR – after action report
- AAR – after action review
- AAS – Army Apprentice School (Australia)
- AAST – aeromedical evacuation administrative support team
- AAT – automatic analog test
- AAT – aviation advisory team
- AAU – analog applique unit
- AAV – amphibious assault vehicle
- AAW – antiair warfare
- AB – airbase
- AB – Airman Basic (USAF E-1)
- ABCA – American, British, Canadian, Australian Armies Program
- ABCS – army battle command system
- ABD – airbase defense
- ABFC – advanced base functional component
- ACF – army cadet force (UK Military)
- ADF – Australian Defence Force (Australia)
- ADFA – Australian Defence Force Academy (Australia)
- ADFC – Australian Defence Force Cadets (Australia)
- ADOS – active duty, operational support
- ADSW – active duty, special work
- AFI – awaiting further instruction
- AFMC – armed forces medical college
- AFOQT – air force officer qualifying test
- AFOSI – Air Force Office of Special Investigations
- AFSC Air Force Specialty Code
- AHA – ammunition holding area
- AIM – airborne intercept missile (U.S. military)
- AIPD – Army Institute For Professional Development
- AIRTC – Air Training Corps (former name for the Australian Air Force Cadets)
- AIT – advanced individual training (U.S. Army)
- Amn – airman (USAF E-2)
- ALCON – All concerned (U.S. military)
- AMU – aircraft maintenance unit
- AMXG – aircraft maintenance group
- AMXS – aircraft maintenance squadron
- An – Antonov (Russian)
- ANZAC – Australian and New Zealand Army Corps
- AOL – absent over leave (U.S. Navy)
- AO – area of operations
- A&P – administrative and personnel
- AP – armor-piercing
- APC – armored personnel carrier
- APFSDS – armour-piercing fin-stabilized discarding sabot
- APO – Army Post Office; See also FPO
- APPN – appropriation number (U.S. Military)
- APRT – Army Physical Readiness Test (U.S. Army)
- ARA – Australian Regular Army (Australia)
- ARes – Army Reserve (Australia)
- ARM – anti-radar missile
- ARM – anti-radiation missile
- ARMS – automated recruit management system (U.S. military)
- ARMS – aviation resource management system (USAF)
- ART – alarm response team (USAF)
- ARVN – Army of the Republic of (South) Viet Nam (U.S. Military)
- ASAP – army substance abuse program (U.S. military)
- ASAP – as soon as possible
- ASEAN – Association of South East Asian Nations
- ASM – air-to-surface missile
- ASCM – anti-ship C missile
- ASV – anti-surface vessel (airborne radar)
- ASVAB – armed services voccasional aptitude battery
- ASW – Anti-submarine warfare
- ATC – ir training corps
- ATC – aiir traffic control
- ATO – air tasking order
- ATO – antiterrorism officer
- ATTRS – army training requirements and resources development
- AWOL – absent without leave
Read more about this topic: List Of U.S. Government And Military Acronyms