| Abbreviation | Definition |
|---|---|
| ARK | Athletes Running For Kids |
| ARPC | Albany Rifle and Pistol Club |
| ARPS | Advanced Role Playing System |
| ARRC | American Road Race of Champions |
| ARRD | Association Rouen Roller Derby |
| ARSC | Arcadia Riptides Swimming Club (California, US) |
| ART | Active Release Technique |
| ART | Advanced Racing Technology |
| ART | Advanced Reflexology Training |
| ARU | Australian Rugby Union |
| ARWL | Akademia Rolnicza W. Lublinie |
| AS | Associazione Sportiva |
| ASA | Aggressive Skater Association |
| ASA | Aggressive Skaters Association |
| ASA | All Softball Associations |
| ASA | Amateur Softball Association |
| ASA | Amateur Swimming Association |
| ASA | American Sailing Association |
| ASA | American Softball Association |
| ASA | American Speed Association |