Firma O - Gjettum
- Olga Iamtsova
- Olsvik Bygg AS
- Oslo Guideinstitutt
- Oslo Guideinstitutt
- Ole Christian Haugan
- Oda Margrethe Lilleaasen
- O.C.Røvang
- Oversetting- Elin Svanes
- Ole Åker Undervisning
- Olga Viktorovna Iamtsova
- Ole Andre Olsvik
- Oslo Writers League
- Oystein Lande Holding AS
- Ooy Thaimassasje Pongchakam
- Oslo Writers League
- Oslo Universitetssykehus HF Ambulansetjenester Bærum
- Orthodox Tewahdo Debre Kdusan Hawaryat
- Orthodox Tewahdo Debre Kdusan Hawaryat