Bedrift O - Billingstad
- Oppegårdssenteret AS
- Osvi Invest AS
- Onsøy Forsvarsforening
- Oscarsgate 3 AS
- Opti Log AS
- Oljonimi Invest AS
- Office Solution AS
- Oslo Trademax
- Ohmygosh Holding AS
- Omtveit Design
- Otm Holding AS
- Oslo Møbelinvest AS
- Oslo Selger Telefon
- Oer Management Reitan
- Octavian - Ovidiu Ciarnau
- Opera Konsulenttjenester Orlien
- One Earth Energy AS
- One Earth Farming AS
- Odberg Jan-Petter
- Operalia Stoyanova-Mincheva
- Ole-Jacob Halgunset
- O Sweet Investments AS
- Ole Jørgen Rise Kirkeby
- Oslo & Akershus Seilkrets
- Olaf & Inga Invest AS
- Ole Deviks vei 18 AS
- Oslo & Akershus Seilkrets
- Ordenen Riddere Av Det Hvite Kors i Norden