Bedrift O - Trollåsen
- Optimila AS
- Omniservice AS
- Oriented AS
- Optimal Økonomiservice ANS
- On-Time AS
- Operasjonssykepleie Myklebust
- Oslo Mynthandel AS
- Orkla Brands
- Oriented Holding AS
- Oslo Bike Rental AS
- Oppegård Tømrerservice AS Konkursbo
- Oppegård Tømrerservice AS Konkursbo
- Oversetter Kari Helene Lauvstad
- Oslo Bygg og Interiør Pieszczek