| ONC | Occupational Nurse Consultant 
| Others |
| ONC | Ocean Nutrition Canada
| Others |
| ONC | Office of National Coordinator
| Others |
| ONC | Office of Neighborhood Coordination
| Others |
| ONC | Office of No Christmas
| Others |
| ONC | Office of the National Coordinator
| Others |
| ONC | Office of the National Coordinator for Health Information Technology
| Others |
| ONC | Omnes Nos Coniunctum
| Others |
| ONC | Oncle ( French: Uncle)
| Others |
| ONC | oncologist
| Others |
| ONC | ONCology
| Others |
| ONC | Only Non-Canadians
| Others |
| ONC | Open Network Computing
| Others |
| ONC | Open Network Configuration
| Others |
| ONC | OpenNet Controller
| Others |
| ONC | Operational Navigation Chart
| Others |
| ONC | Operational Navigation Charts
| Others |
| ONC | Optical Navigation Camera
| Others |
| ONC | Optical Network Certification
| Others |
| ONC | Ordinal And Non Comparable
| Others |
| ONC | Ordinary National Certificate
| Others |
| ONC | Oregon Nordic Club
| Others |
| ONC | Organization of National Clinics
| Others |
| ONC | Orthopaedic Nurse Certified
| Others |
| ONC | Orutsaramiut Native Council
| Others |
| ONC | Orutsararmiut Native Council
| Others |
| ONC | Otsego Northern Catskills
| Others |