| Acronym | Definition |
|---|
| ORTA➣Oak Ridges Trail Association (Canada) |
| ORTA➣Ohio Retired Teachers Association (Columbus, OH) |
| ORTA➣Olympic Roads and Transport Authority (Australia) |
| ORTA➣Office of Research and Technology Application |
| ORTA➣Ohio Rehabilitation Technology Association |
| ORTA➣Ohio Rail Tourism Association (est. 1999) |