English abbreviations from on to ons
- ON (Ontario (postal symbol))
- ONA (Winona Municipal Airport (Max Conrad Field))
- ONAN (Oil Natural Air Natural cooled transformer)
- ONB (Operation New Birmingham)
- ONBGFF (Old NewsBoys' GoodFellow Fund)
- ONC (Orthopaedic Nurse Certified)
- ONCE (Organización Nacional de Ciegos Españoles (Spanish, "National Organization for the Spanish Blind"))
- ONE (Orientation for Nutrition Employees)
- ONEA (Organizacion Nacional de Estudiantes Ambientales y Carreras Afines)
- ONÉRA (Office national d'études et de recherches aérospatiales (French, "Aeronautics and Space Research Center"))
- ONF (Oncology Nursing Forum)
- ONG (Orthodontic National Group)
- ONH (Historically, as the Irish-language name for the original Irish Republican Army ("Old IRA"))
- ONI ((U.S.) Office of Naval Intelligence)
- ONJ (Odate-Noshiro Airport)
- ONK (Olenyok Airport)
- ONL (O'Neill Municipal Airport (John L. Baker Field))
- ONM (Socorro Municipal Airport)
- ONMC (Official NASCAR Members Club)
- ONN (Onion Bay Airport)
- Onna (Oniong, Nnung Ndem, and Awa, a Local Government Area in Nigeria)
- ONNR (Office of Natural Resources Revenue (formerly MMS))
- ONO (Ontario Municipal Airport)
- ONP (Newport Municipal Airport)
- ONQ (Zonguldak Airport)
- ONS (Operational Needs Statement)