Bedrift O - Sem
- Odd Rui AS
- Olborg Invest AS
- Ollebukta 4 AS
- Olha Lieskova
- Onyx Morningstar AS
- Origo Næringspark AS
- Overhill Holding AS
- Omega Tds AS
- Olsen Byggservice As
- Okab-Bvt
- Olympia Sport AS
- Omega Holtan AS
- Omega Akerholdt AS
- Olai Holding AS
- Ola Flåten
- Ole Knut
- Ole Reino Tala
- Origo Horten Invest AS
- Ole Arne Hotvedt
- Ole Andreas Hotvedt
- Olsen Byggservice Prosjekt AS
- Olimb Rørfornying øst AS
- Oslo City Fashion A/S
- Ole Christian Torkildsen
- Odd Inge Bergan
- Ole Brattekværne Jr
- Ofstad Hydraulic Support
- Omega B.i.L
- Ole & Vidars Hageservice DA
- Omli gård Anders Magnusson
- Opplæringskontoret for Håndverksfag i Vestfold
- Opplæringskontoret for Tømrerfaget i Vestfold
- Opplæringskontoret for Rørleggerfagene i Vestfold