Bedrift O - Krokstadelva
- Outreachasia
- Outreachasia
- Onstage AS
- Orionfeltet Velforening
- Ok Elektriske AS
- Ok Elektriske AS
- Oui Clothing
- Oddbjørn Pedersen
- Oddbjørn Pedersen
- OPK-Instituttet
- Octavian Popa
- Opk-Instituttet AS
- Ottesen Trading AS
- Obrebski Michal
- Olm Group AS
- Olav Stuveseth AS
- Outlet Service AS
- Omega Power AS
- Ottar Christopher Vogt
- Ole Peder Døviken
- Ole Kristian Temte
- O S Skogsservice DA
- Olaf Helge Ask AS
- Ole Andreas Stølen
- Olsson Ulf Henning
- Ole Christian Westerhus
- Ok Permanent Kravenska
- Op Motzfeldt Holding AS
- Ole Kristian Stoltenberg
- Ole Johan Eknæs
- O2 Sport Norge AS
- Ok Varmeteknikk Erik Schenk
- Os Design, Ola Stuveseth
- Ole-Jørgen Schulsrud-Hansen
- Ortoped Ingi Thor Olafsson
- Ole Ivar Bergan Holding AS
- Oda E. Wang Holding AS
- O.A Hagen Consulting
- Opad Ole Petter Aarvold Diseth