Contacts under O
- Ofcom (Office of Communications) NI
- Office of Care and Protection
- Office of the Lord Chief Justice - complaints officer
- Office of the Mental Health Champion
- Office of the Northern Ireland Executive in Brussels
- Ofgem
- Omagh Careers Office
- Omagh Court
- Omagh Hospital and Primary Care Complex
- Omagh Jobs & Benefits office
- Omagh Local Area Planning Office
- Omagh Registration office
- Ombudsman (Northern Ireland)
- Open University (OU) - Open University (Northern Ireland)
- Organised Crime Task Force
- Outdoor Recreation NI
- OwnCo