| Acronym | Definition |
|---|
| ONA | Office of National Assessments (Australia) |
| ONA | Office of Negotiations and Agreements (Foreign Agricultural Service, United States Department of Agriculture) |
| ONA | Office of Net Assessment |
| ONA | Office of Network Administration |
| ONA | Ohio Nurses Association |
| ONA | Oklahoma Nurses Association |
| ONA | Omnium North Africa |
| ONA | On-Line Archive |
| ONA | Onondaga Numismatic Association |
| ONA | Onsite Network Administrator |
| ONA | Ontario Nurses Association |
| ONA | Open and Affirming |
| ONA | Open-Network Architecture |
| ONA | Operational Net Assessment |
| ONA | Optical Network Architecture |
| ONA | Optimal Nutritional Allowance |
| ONA | Order of the Nine Angles (Satanism) |
| ONA | Oregon Nurses Association |
| ONA | OSI Network Address |
| ONA | Other Needs Assistance (US FEMA program) |
| ONA | Outreach North America (Associate Reformed Presbyterian Church) |
| ONA | Outreach to New Americans (National Crime Prevention Council, Bureau of Justice Assistance and the Office of Refugee Resettlement) |
| ONA | One Number Access |
| ONA | Online Network Access |