Bedrift O - Nesbru
- Onarts AS
- Olisatek AS
- Octano AS
- Oliver AS
- Odalen AS
- Omn AS
- Odina AS
- Oppkomme AS
- Okie AS
- Open AS
- Onarts AS
- Owe AS
- Olav Øvreberg
- Oskars Forstmanis
- Oli Holding AS
- Oslo Bridgeklubb
- Oslo Bridgeklubb
- Ozon Gruppen AS
- Ola Grønseth
- Oddsten Consulting AS
- Optimal Totalentreprenør AS
- Odga Holding AS
- Ozon Kube AS
- Oxs Holding AS
- Ozon Transport AS
- Olivia Stone
- Olsen Yngve Holte
- Ola Nordvang Rundfloen
- O Poulsen Holding AS
- Olav K Brekke AS
- O Poulsen Consult AS
- Oliver og Farfar AS
- OK Minilager Billingstad
- OK Minilager Nesbru
- Olav Christian Nordtorp Houge
- Oslo Asset Management Holding AS
- Optiker G Krogh Holmen
- Optiker G Krogh Holmen
- Oslo Lokallag Av Landslaget for Offentlige Pensjonister