Bedrift O - Frogner
- Ozonvann AS
- Objectfront AS
- Ole Vardøy
- Olsen Tommy
- Osloveien 10 AS
- Oppegård Invest AS
- Ozols Edgars
- Osdalen Hytteeierforening
- Oslo Communication AS
- Oslo Storbilvask AS
- Ove's Sportsfiske AS
- Oslo Varmeservice AS
- Oslo Snekkerverksted AS
- Oa Betong AS
- Otd Akademiet AS
- Oslo Betongtransport AS
- Olav Berger
- Ozols Edgars
- Optimal Bedriftservice AS
- Optimal Bedriftservice AS
- Ole-Gunnar Holm
- Ola Martin Brændjord
- Oslo Volkswagen Club
- Oppmerking og Skilt AS
- Ole Per Hustad
- Ole-Harald Rustad
- Ok Romsaas Holding AS
- Ole-Kristian Romsaas
- Oslo West Finest
- Olegs Podskocevs Konkursbo
- Oslo West Finest
- Olegs Podskocevs Konkursbo
- Ole-Kr Romsaas
- Opp & Ned AS
- Oslo Seafood Center AS
- O.A.Nysæther AS
- Oslomarka Trekkhundklubb Oldermannsliga
- Olsen Grønn Fremtid Vegard
- Oslo Bilspektrum Waseem Mahmood
- Opplæringskontoret for Elektrofag Romerike
- Ozo Transport Andis Ozols
- Oslo og Viken Låsservice AS
- Oslo og Akershus Langholdsklubb
- Olai Tisthammer Massasje og Renhold
- O2 Medic & Rescue Olstad
- Opplæringskontoret for Tele, Data og Elektro