Bedrift O - Fjellhamar
- Ornio AS
- Olivos AS
- Omnicus AS
- Objekt Invest AS
- Ovidijus Petrikauskas
- Oleksii Poiminov
- Octavian Tudorache
- Ole Nordby
- Olha Shumylo
- Oslo Rør&Bad AS
- Olha Komurko
- Oc Bjeglerud
- Oi Design AS
- Obrien Consulting
- Obj Holding AS
- Olsense Technology AS
- Oasen Frisør AS
- Otterstad Markus
- Olekandra Kuslii
- Okh Holding AS
- OCH Invest AS
- Orooj Mahmood AS
- Ornela Bekari
- Oskar Grønning
- Olsberg Auto
- Olsen Vidar
- Olason Holding
- Octavian Tudorache Services
- Ole Enrico Nyborg
- Ole Stubberud Landbrukstaksering
- Otterlei Glenn Roger
- Optiker Gunnhild Vik
- Oslo HiFi Show AS
- O. Trudvang Invest AS
- Oscar Winther Nguyen
- Ole Kristian Storli
- Odd Arne Lauritzen
- Oslo Sivile Redningshunder
- Ole Jørgen Baarlid
- Oslo Rock City
- Oslo Rør & Bad AS
- Ole Jørgen Holt Hanssen
- Ole Martin Nilsen Synnes
- Orkid Nails Anna Kozlowska
- Oslo Bygg og Vedlikehold AS
- Oslo&Akershus Hvitevare Service Vijihananthan Vijeyaratnam
- O.M. Sanne R & R