| Abbreviation | Definition |
|---|---|
| ACLF | Amicale Cadillac Lasalle France |
| ACLU | Anti Christian Lawyers United |
| ACLU | Anti Christian Lifestyle Union |
| ACMC | American Cruisers Motorcycle Club |
| ACME | Amazing Canadian Mountain Expedition |
| ACMS | Associated Clan Macleod Societies |
| ACP | Automovel Clube de Portugal |
| ACRG | American Culture Reading Group |
| ACRR | Ancient City Road Runners |
| ACRR | Automobil Clubul Regal Roman |
| ACRW | American Christian Romance Writers |
| ACS | American Cockatiel Society |
| ACS | Ant Construction Set |
| ACU | Auto Cycle Union |
| ACVL | Association Canadienne de Vol Libre |
| ACVW | Air Cooled Volkswagen |
| ADMS | American Donkey and Mule Society |
| ADRA | Alberta Dirt Riders Association |
| ADRF | Aruba Drag Race Foundation |
| AE | Airsoft Elite |