Bedrift O - Torshov
- Ohvholding AS
- Ontopia AS
- Owh AS
- Outrun AS
- Odo AS
- Oransjevin AS
- Ojfango AS
- Oslopensjonistene
- Oslopensjonistene
- Osman
- Oxbull AS
- Oda Brenn
- Overskott Lyd
- Oslo Kampsportklubb
- Oslo Rørservice AS
- Olena Pertsuk
- Owh Consulting AS
- Oslo Aula AS
- Oda Brenn
- Opc Megaphon AS
- Oslo Prime AS
- Oslo Prime AS
- Oegema Music
- Ot2 Mathisen
- Oga Holding AS
- Oslo Fagottkor
- Overtone Vik
- Osman Film
- Ommundsen Arkitektur
- Oev Invest AS
- Omb Invest AS
- Oslo Hageservice
- Ovenstad Familieterapi
- Olena Kurmanenko
- Orange Fx
- Opsahl Fotografi
- Oslo Backgammonklubb
- Oslo Rør AS
- Olena Horilska
- Oslo Jazzdansfestival
- Oslo Jazzdansfestival
- Oslo Kantiner AS
- Ola Vestad
- Olivia McIntyre
- Onh Invest AS
- Ogaden Releif
- Ousland Fysioterapi
- Oslo Rullestolrugbyklubb
- Oleh Shust
- Oliver Magnussen
- Oksana Trylysenko
- Oh Bøyesen
- Ola Samuelsen
- Omumu Solutions AS
- Oslo Squash Klubb
- Ola Dreng Feen
- Osteopat Bettina Tømte
- Ole Henrik Dyrseth
- Oliver Halvorseth Sunde
- Odin Dillingøens Fotspor
- Olav Nylund Dale
- Ola Aasmo Sundheim
- Oskar Braaten Barnehage
- Ole Petter Anfinsen
- Oscar Romero Diaz
- Oda Erlendsdotter Urke
- Ola Geir Raftevold
- Oslo Privatservice Anbakk
- Odilon Creations Norway AS
- Oscar Frisør Salong
- Oslo Nye Trikkestallen
- Oda Sofie Granholt
- Odd Andreas Sivertsen
- Oralkirurg Laszlo Kalmar
- Olav Kolbjørn Haugeto
- Ole Martin Vilberg
- Oxlo Rugs Nyhaug
- Ollendorff Knut Harald
- Ole Andreas Sørhuus
- Ole Steen Studio
- Ole Andreas Høyberg
- Oslo Live Music AS
- Oslo Kommunale Leieboerorganisasjon
- Ortodoxiev Ognian Prodanov
- Ole Normann Skrebergene
- Osteopat Richard Hveding
- Oslo Betonginteriør Gudbrand Kaas
- Ole Aklilo Qvale Lineikro
- Oslo AS House Of Pain
- Oss Nordic AS Ansatt 2
- Oslo The Escape Games
- Ocbk Design B. Kjelstad
- Observatoriet 2 Jan Alsaker
- Ole-B. Alfredsen Tømmerservice
- Oslo Overgangsbolig Torshov Avdeling
- Opplysning Om Kosthold og Matfrihet
- Oslo Vaktmestertjeneste Harald Johan Branes
- Oslo øst Rugby League Klubb
- Ornella Lalisa Ornella Lalisa Hjelpdahl
- Orkla Home & Personal Care AS Avd Handelsvaresalg
- On My Way Cab Jan Dus
- Ol Burger Beats Ole-Birger Neergård