| APTA | Access Piqua Television Association 
| Others |
| APTA | Ajax Pickering Transit Authority
| Others |
| APTA | Alabama Police Trainer's Association
| Others |
| APTA | Alligator Point Taxpayers' Association
| Others |
| APTA | American Physical Therapy Association
| Others |
| APTA | American Platform Tennis Association
| Others |
| APTA | American Polarity Therapy Association
| Others |
| APTA | American Public Transit Association
| Others |
| APTA | American Public Transportation Association
| Others |
| APTA | Angst, Pain, and Torture Association
| Others |
| APTA | Applied Petroleum Technology Academy
| Others |
| APTA | Asia-Pacific Trade Agreement
| Others |
| APTA | Association for Promotion of Tourism to Africa
| Others |
| APTA | Association for the Preservation of Tennessee Antiquities
| Others |
| APTA | Association for the Promotion of Tourism to Africa
| Others |
| APTA | Atlantic Provinces Trucking Association
| Others |
| APTA | Austrian Platform for Telematics Application
| Others |
| APTA | Automotive Products Trade Agreement
| Others |
| APTA | The American Physical Therapy Association
| Others |