Bedrift O - Finstadjordet
- Ozdarbiev Biegård
- Oslo Paintball AS
- Ollendorff Holding AS
- Ors International AS
- Ollendorff Eiendom AS
- Oksrødkilen Hytteeierforening
- Octavio Cervantes
- Omax Imran Farooq
- Onpoint Xhedeon Mata
- O Smulan Multiservice
- Osteopat Mia Syverud
- Oscars gate 19 AS
- Omar Ahmed Akkouh
- Ole-Kristian Bergaust Thomassen
- Oslo Taxi A541 Malkiat Singh