| ACTO | Action Officer 
| Others |
| ACTO | Advocacy Centre for Tenants Ontario
| Others |
| ACTO | Alliance of Concerned Transport Operators
| Others |
| ACTO | Alliance of Concerned Transport Organizations
| Others |
| ACTO | Amazon Cooperation Treaty Organisation
| Others |
| ACTO | Amazon Cooperation Treaty Organization
| Others |
| ACTO | Angeles City Tourism Office
| Others |
| ACTO | Army Communicative Technology Office
| Others |
| ACTO | Association for Counselling and Therapy Online
| Others |
| ACTO | Association of Clinical Trials Organizations
| Others |
| ACTO | Association of Coach Training Organizations
| Others |
| ACTO | Association of Competitive Telecom Operators
| Others |
| ACTO | Association of Container Train Operators
| Others |
| ACTO | Attractive to Criminals and Terrorist Organizations
| Others |