Bedrift O - Torshov
- Ohvholding AS
- Ontopia AS
- Outrun AS
- Orrelie AS
- Odo AS
- Oransjevin AS
- Ojfango AS
- Osman
- Oxbull AS
- Oda Brenn
- Olena Pertsuk
- Overskott Lyd
- Opc Megaphon AS
- Oslo Prime AS
- Oslo Kampsportklubb
- Oslo Rørservice AS
- Oslo Prime AS
- Omar Mohammad
- Oga Holding AS
- Oslo Fagottkor
- Oslo Jazzdansfestival
- Overtone Vik
- Oev Invest AS
- Osman Film
- Omb Invest AS
- Ommundsen Arkitektur
- Oslo Jazzdansfestival
- Oslo Hageservice AS
- Ovenstad Familieterapi
- Olena Horilska
- Olena Kurmanenko
- Oslo Backgammonklubb
- Opsahl Fotografi
- Oslo Rør AS
- Orange Fx
- Onh Invest AS
- Ola Vestad
- Oslo Kantiner AS
- Oslo Rullestolrugbyklubb
- Oleh Shust
- Oksana Trylysenko
- Ousland Fysioterapi
- Ogaden Releif
- Omumu Solutions AS
- Ola Samuelsen
- Oh Bøyesen
- Osteopat Bettina Tømte
- Ole Henrik Dyrseth
- Oliver Halvorseth Sunde
- Oslo Squash Klubb
- Olav Nylund Dale
- Oskar Braaten Barnehage
- Ole Petter Anfinsen
- Olaf Andreas Strand
- Oslo Cycling Week
- Oslo Cycling Week
- Omar Travel Agency
- Oscar Romero Diaz
- Oslo Privatservice Anbakk
- Ola Geir Raftevold
- Oscar Frisør Salong
- Ole Calmeyer Haagenrud
- Olav Skillingstad Andersen
- Oslo Nye Trikkestallen
- Oralkirurg Laszlo Kalmar
- Oxlo Rugs Nyhaug
- Ole Martin Vilberg
- Olav Kolbjørn Haugeto
- Oda Sofie Granholt
- Odd Andreas Sivertsen
- Ollendorff Knut Harald
- Ole Andreas Høyberg
- Ole Andreas Sørhuus
- Oslo Live Music AS
- Ole Steen Studio
- Ortodoxiev Ognian Prodanov
- Oslo Kommunale Leieboerorganisasjon
- Osteopat Richard Hveding
- Oslo Betonginteriør Gudbrand Kaas
- Osteopat Elsa Ruz Rojas
- Ole Aklilo Qvale Lineikro
- 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