Firma O - Vøyenenga
- Olav Carlsson
- Oslo Bilutleie AS
- O. Reistad AS
- Outlet Invest AS
- Oslo Glasscoating ANS
- Ophelia Frisørene AS
- Ordsmeden Thorgeir Holm
- Ocz Storage Solutions INC
- Oppussing -Bygg Vahabi
- Oyama Karate Bærum
- O. Johanssen Bakery AS
- Ole Gunnar Honningsøy
- Oyama Karate Bærum
- Oro Posters By Rögnvaldsson
- Optimax - Bedriftsrådgiving Steinar Bang Fylling
- Ot Brands Ola-Tobias Brandsæter
- Oslo Bærum Vann & Varme AS