Bedrift O - Furuset
- Octopus AS
- Oterra
- Orogenic AS
- Omari
- Omnicus AS
- Olena Petrivska
- Oleskiy Cherepukhin
- Oslo Bilservices AS
- Osman Sebaydin
- Oppsiden Eiendom AS
- Oleksandr Kizino
- Olena Pikunova
- Odin Entreprenørfirma AS
- Oslo Båtimport
- Olsen Rune
- Oslo Fryselager AS
- Oleg Sveiseverksted
- Ok Soldrift AS
- Oslo Workwear AS
- Oslo Snekkere AS
- Oslo Båtimport AS
- Oslo Lagerhotell AS
- Oslo Cab AS
- Oslo Sanitetslag Alarmtelefon
- Oz Kvalitet Mehmed
- Oslo Rock Service AS
- Oddgeir Schei Eiendom AS
- OK Bingo Arkaden
- O Kristoffersen Bingodrift AS
- Oslo VVS Senter AS
- Olaf Johansens Eftf. AS
- Oslo Prime Holding AS
- Oslo Alna Rotary Klubb
- Oslo Sweets & Bakers AS
- Omar Mohamed Redouan Ben
- Ofbjp Mahila Morcha Norway
- Oslo Viken Taxi Elaachmiri
- Oslo Bud O Ren AS
- Oslo City F.C.
- Olaf Johansen Eftf AS Avd Produksjon
- Olaf Johansens Eftf AS Avd VVS
- Oslo Bygg og Montasjeservice AS
- Oslo B Service AS Konkursbo
- Oslo B Service AS Konkursbo
- Oslo City F.C.
- Oromisk Muslimsk Samfunn i Norge
- Oslo & Viken Transporttjenester Asrar Ahmed
- Oslo & Viken Bad og Flis AS