Bedrift O - Torp
- Ole & Co AS
- Onlywater DA
- Olsen Kari
- Oliversuite Norge AS
- Oha-Holding AS
- Ole & Co Prosjekt AS
- Olav Veberg
- Olsen Express
- Olav Aas
- Opstad Helse
- Ophus Multiservice
- Optimal Entreprenør AS
- Olsen Glenn Rino
- Odd Arne Linstad
- Oversetterbyrå Joachim Stene
- Oliver Andreas Thunæs
- Oremo Outboard Service
- Oremoveien Va SA