| OATC | Oceanic Air Traffic Center 
| Others |
| OATC | Office Admin Technology Conc
| Others |
| OATC | Office of Assessment Trinity College
| Others |
| OATC | Offshore Africa Training Centre
| Others |
| OATC | Ohio Association of Teachers of Chinese
| Others |
| OATC | Oklahoma Assistive Technology Center
| Others |
| OATC | Olathe Advanced Technical Center
| Others |
| OATC | Ontario Addiction Treatment Centres
| Others |
| OATC | Open Authentication Technology Committee
| Others |
| OATC | Opioid Addiction Treatment Collaborative
| Others |
| OATC | Oracle Applications and Technology Consulting
| Others |
| OATC | Order of the Arrow Trail Crew
| Others |
| OATC | Oregon Advanced Technology Center
| Others |
| OATC | Oregon Advanced Technology Consortium
| Others |
| OATC | Oregon Association of Tax Consultants
| Others |