AOA
- AOA (group)
- Act of Aggression
- Adam-Ondi-Ahman
- Administration on Aging
- Age of Apocalypse
- Age of acquisition
- Agreement on Agriculture
- Airport
- Airport Operators Association
- Alpha Omega Alpha
- American Optometric Association
- American Osteopathic Association
- American Outlaws Association
- American Overseas Airlines
- Analysis of Alternatives
- Andrews Osborne Academy
- Angle of arrival
- Angle of attack
- Angolan kwanza
- Aniplex of America
- Aoa affinis
- Armies of Arcana
- Articles of association
- As-salamu alaykum
- Australian Orthopaedic Association
- Automated online assistant
- Auxiliary Organizations Association
- Nitrification
- Space Shuttle abort modes
- The Axis of Awesome
- ʻAoa