| Acronym | Definition |
|---|
| ONAC | Organismo Nacional de Acreditación de Colombia (Spanish: National Accreditation Agency of Colombia) |
| ONAC | Operations Network Administration Center |
| ONAC | Office National des Anciens Combattants et Victimes de Guerre (French: National Office of Veterans Affairs and War Victims; Ministry of Defense; France) |
| ONAC | Oklevueha Native American Church |
| ONAC | Office of Noise Abatement and Control |
| ONAC | Oregon Native American Chamber |
| ONAC | Organización Nacional Campesina (Spanish: National Farmers Organization; Paraguay) |
| ONAC | One Nation Archery Club (UK) |
| ONAC | Operations Network Administration Center (AT&T) |
| ONAC | Open North American Championship (dog sledding; Alaska) |
| ONAC | Oklahoma Nursing Articulation Consortium |