Bedrift O - Fagerstrand
- Ombrello
- Ormhamar Hytteforening
- Oppdal Aleksander
- Otto Bratberg
- Olha Liakhusjyna
- Olha Konevalyk
- Oy-Hal AS
- On24 Norge AS
- Olsby Konsult
- Oplund Eiendom AS
- Olsen Elektro AS
- Organicbeleafs Kandil Eriksen
- Ole Christian Eklund
- Orange Studio Treningssenter
- Oslo Follo Industri AS
- Ottestads Håndverk Service Fred