| Norco Security Ans | Wholesale & retail | 1998 |
| Nordic Needle AS | Other services | 2026 |
| Nordic Outdoor AS | Wholesale & retail | 1992 |
| Nordic Wireless Solutions AS | Manufacturing | 2004 |
| Nordiq Commerce AS | Professional & scientific | 2026 |
| Nordvind Eiendom AS | Real estate | 1987 |
| Nordvind Holding AS | Professional & scientific | 2011 |
| Norfos Holding AS | Other services | 2021 |
| Noritech AS | Construction | 2019 |
| Norse Atlantic Airways AS | Transport & logistics | 2021 |
| Norse Atlantic ASA | Transport & logistics | 2021 |
| Norse Atlantic Us Holding AS | Transport & logistics | 2021 |
| Norse Corporation AS | Professional & scientific | 2023 |
| Norse Marine AS | Professional & scientific | 2022 |
| Norse Marine Services AS | Professional & scientific | 2011 |
| Norse Project AS | Professional & scientific | 2023 |
| Norsk Bremsekontroll AS | Professional & scientific | 2009 |
| Norsk Dental AS | Wholesale & retail | 2015 |
| Norsk Flid Husfliden Arendal AS | Wholesale & retail | 1991 |
| Norsk Insektvern AS | Professional & scientific | 2025 |
| Norsk Kirkegårdsservice AS | Administrative & support | 2009 |
| Norvege AS | Real estate | 2023 |
| Norway Marine Supply AS | Wholesale & retail | 1984 |
| Norway Seaweed AS | Agriculture & fishing | 2015 |
| Novah Design AS | Wholesale & retail | 2020 |
| Novarett Holding AS | | 2025 |
| Nse Equipment AS | Administrative & support | 2007 |
| Nse Fagstillas AS | Construction | 1989 |
| NV Lager Øst AS | Real estate | 2023 |
| Nye Blå Tråd AS | Wholesale & retail | 2011 |
| Nye JR Hellevik Holding AS | Health & social care | 2017 |
| Nye Regnskapstjenester AS | Professional & scientific | 2026 |
| Nygaten 5 Arendal AS | Real estate | 2017 |
| Nygårdsveien 49 Arendal AS | Real estate | 2022 |
| Nyli Garasjelag SA | Other services | 1973 |
| Nyli Gård AS | Hospitality | 1999 |
| Nyli Gård Eiendom AS | Real estate | 2025 |
| Nyvik Eiendom AS | Real estate | 2016 |
| Nå Padel Arendal AS | Real estate | 1998 |
| Nødlysteknikk AS | Manufacturing | 1991 |
| O G Ottersland Eiendom AS | Real estate | 1979 |
| O&M Group AS | Professional & scientific | 2024 |
| O. G. Ottersland AS | Real estate | 2019 |
| O.G.Ottersland Drift AS | Real estate | 1998 |
| Oak Agency AS | Wholesale & retail | 2015 |
| Odd Fellow Huset AS | Real estate | 1981 |
| Offshore & Heavylift Services AS | Transport & logistics | 2012 |
| Offshore Kinetics AS | Professional & scientific | 2009 |
| Ofp Produkt AS | Professional & scientific | 2022 |
| Oh Spell AS | Professional & scientific | 2019 |
| Olav Ager-Wick AS | Construction | 1980 |
| Olav Stormo AS | Wholesale & retail | 1977 |
| Olimstad Holding AS | Construction | 2023 |
| Olweus Group AS | Information & communication | 2020 |
| Omdalsmoen Honning AS | Agriculture & fishing | 2022 |
| Oneco Infra AS | Construction | 2011 |
| Oneg Holding AS | | 2024 |
| Onyx Real AS | Real estate | 2021 |
| Oralkirurg Ove Busch AS | Health & social care | 2018 |
| Oscars Gate 52 AS | Real estate | 2018 |
| Osm Aviation Academy AS | Education | 2017 |
| Osm Aviation Academy Holding AS | Education | 2017 |
| Osm Aviation Airtech AS | Manufacturing | 2018 |
| Osm Crew Management AS | Administrative & support | 1990 |
| Osm Marine Crew 2 AS | Administrative & support | 2016 |
| Osm Marine Crew 3 AS | Administrative & support | 2018 |
| Osm Marine Crew 4 AS | Administrative & support | 2006 |
| Osm Marine Crew 5 AS | Administrative & support | 2019 |
| Osm Marine Crew 6 AS | Administrative & support | 2019 |
| Osm Marine Crew 7 AS | Administrative & support | 2021 |
| Osm Marine Crew 8 AS | Administrative & support | 2022 |
| Osm Marine Crew AS | Administrative & support | 2007 |
| Osm Maritime AS | Transport & logistics | 2015 |
| Osm Maritime Group AS | Transport & logistics | 2015 |
| Osm Offshore AS | Transport & logistics | 2004 |
| Osm Ship Management AS | Transport & logistics | 1977 |
| Osm Ship Management B AS | Transport & logistics | 1991 |
| Otra Buss AS | Transport & logistics | 2005 |
| Otterlei Group AS | Wholesale & retail | 1999 |
| Otterlei Industries AS | Manufacturing | 2018 |
| Otto Eliassen AS | Real estate | 1988 |
| Otto F R C Holding AS | | 2026 |
| Oveland Eiendom AS | Real estate | 2004 |
| P Holding & Investments AS | Hospitality | 2024 |
| P Hus Vest AS | Transport & logistics | 1997 |
| Padlespesialisten AS | Wholesale & retail | 1998 |
| Pal-Holding AS | | 2025 |
| Palass AS | Real estate | 2004 |
| Palladium Frisør AS | Other services | 2023 |
| Pan Invest AS | Real estate | 2002 |
| Pan Nordic Securities AS | Financial services | 1997 |
| Panponic Biosystems AS | Professional & scientific | 2016 |
| Panterra AS | Manufacturing | 2013 |
| Paradis Norway AS | Wholesale & retail | 2012 |
| Parlow Finans AS | Transport & logistics | 2005 |
| Paro Restaurant Drift AS | Hospitality | 2010 |
| Pasientskadehjelpen AS | Professional & scientific | 2025 |
| Patientia AS | Professional & scientific | 2017 |
| Peder Bogensgt. Eiendom AS | Real estate | 2011 |
| Peder Thommassonsgate 12 AS | Real estate | 2007 |