Bedrift O - Gullaug
- Oliver Grundnes
- Ottias Tapfumanei
- Oleksii Chebir
- Oléka Holding AS
- Olsen-Aktiv
- Orica Norway AS
- Ormstads Service
- Ole Herman Fjelltun
- Ole-Håvard Dale
- Orsi Parkanyi Consulting
- Orienteringskonsulent Kenneth Buch
- Orica Norway AS Avd Sætre
- Otarie Media Monica E Lygell
- Oddvar Kallestad Tømrer O Kallestad
- Offshore Explosives Consultancy Jerry Hurum
- Odd Eagle Productions Ulf Ørnodd Langsrud
- Orica Norway AS Avd Orica Norway Salg og Sprengstof