| Abbreviation | Definition |
|---|---|
| AOA | American Osteopathic Association |
| AOA | American Outlaws Association |
| AOA | Apartment Owners Association |
| AOA | Asia and Oceania Association |
| AOAA | Association of Air Ambulances |
| AOAB | Aviation Operators Association of Bangladesh |
| AOAP | Association of Aquatic Professionals |
| AOB | Association of Brewers |
| AOBE | Association of Brownsville Educators |
| AOBM | Association Of British Muslims |
| AOBP | Association of Bridging Professionals |
| AOBS | Association of Oldetime Barbell and Strongmen |
| AOC | Association Of Colleges |
| AOC | Association of Old Crows |
| AOCA | All Odisha Chess Association |
| AOCA | Army Otter Caribou Association |
| AOCE | Association of Oregon Corrections Employees |
| AOCI | Association of Clergy International |
| AOCM | Association of Online Community Moderators |
| AODC | Association of Offshore Diving Contractors |