| ARPA | A Research Projects Agency 
| Others |
| ARPA | Adaptive Resource Protection Agent
| Others |
| ARPA | Address and Routing Parameter Area
| Others |
| ARPA | Address Resource Program Access
| Others |
| ARPA | Advance Rehearsal Project Approval
| Others |
| ARPA | Advance Research Projects Agency
| Others |
| ARPA | Advanced Rapid Process Agent
| Others |
| ARPA | Advanced Research Projects Administration
| Others |
| ARPA | Advanced Research Projects Agency
| Others |
| ARPA | Amazon Region Protected Areas
| Others |
| ARPA | American Racing Press Association
| Others |
| ARPA | Amicale Retro Peugeot Atlantique
| Others |
| ARPA | Archaeological Resources Protection Act
| Others |
| ARPA | Arizona Rock Products Association
| Others |
| ARPA | Arno Ruitenberg Picture Art
| Others |
| ARPA | Association of Representatives of Professional Athletes
| Others |
| ARPA | Atlantic Region Philosophers Association
| Others |
| ARPA | Augmented Reality Pedagogical Agent
| Others |
| ARPA | Automatic Radar Plotting Accessory
| Others |
| ARPA | Automatic Radar Plotting Aid
| Others |
| ARPA | Average Revenue Per Account
| Others |