| Non Stop Transport AS | Wholesale & retail | 2019 |
| Nonsk Inneklima AS | Construction | 2024 |
| Nor Frisør AS | Other services | 2016 |
| Nor&Mint AS | Manufacturing | 2023 |
| Nord Kapital AS | Real estate | 2017 |
| Nordest Ehitus Oü | Construction | 2005 |
| Nordic Facility Services AS | Professional & scientific | 2022 |
| Nordic Office Supplies AS | Manufacturing | 2009 |
| Nordic Offshore Systems AS | Professional & scientific | 2026 |
| Nordic Solergy AS | Wholesale & retail | 2022 |
| Nordic Structures AS | Professional & scientific | 2020 |
| Nordiqo Group AS | | 2023 |
| Nordisk Frisør AS | Other services | 2025 |
| Nordlie-Invest AS | | 2026 |
| Nordlit AS | Construction | 2015 |
| Nordstrand Kobber & Blikk AS | Construction | 2023 |
| Nordwagen AS | Wholesale & retail | 2024 |
| Nordx AS | Professional & scientific | 2025 |
| Norexa AS | Wholesale & retail | 2026 |
| Norges Naprapatforbunds Servicekontor AS | Professional & scientific | 2019 |
| Normann Holding AS | | 2005 |
| Normedin AS | Wholesale & retail | 1989 |
| Norsk Foodservice AS | Wholesale & retail | 2014 |
| Norsk Mose & Design AS | Manufacturing | 2018 |
| Norsk Ortopedisk Fottøy AS | Manufacturing | 2018 |
| Norsk Stål Tynnplater AS | Manufacturing | 1996 |
| Norsk Teknisk Porselen AS | Manufacturing | 1923 |
| Norsk Teknisk Porselen Products AS | Manufacturing | 2013 |
| Norsol Eiendom AS | Real estate | 1996 |
| North Hills Capital AS | Professional & scientific | 2023 |
| Northstar Trading Ans | Wholesale & retail | 1997 |
| Norumen AS | Administrative & support | 2010 |
| Norvisjon AS | Real estate | 2012 |
| Norwang Holding AS | | 2025 |
| Norwegian Consulting AS | Professional & scientific | 2018 |
| Not Basic AS | Financial services | 2023 |
| Nova Medic AS | Health & social care | 2018 |
| Novity-Import Ans | Wholesale & retail | 2005 |
| NTP Holding AS | Manufacturing | 2005 |
| Numerica AS | | 2020 |
| Nummer 33 AS | Real estate | 2020 |
| Nummer 34 AS | Real estate | 2019 |
| NUMMER16 AS | | 2020 |
| Nunatak AS | Professional & scientific | 2001 |
| Nunatak Holding AS | Information & communication | 2005 |
| Nybar AS | Hospitality | 2019 |
| Nye Adm AS | Professional & scientific | 2025 |
| Nye Warda Ans | | 1993 |
| Nygaardsgata 34 AS | Hospitality | 2007 |
| Nygaardsgata 45 AS | Real estate | 2011 |
| Nygaardsgata Holding AS | Real estate | 2019 |
| Nygaardsgaten 1 AS | Real estate | 2010 |
| Nygaardsgaten 23-27 AS | Real estate | 2020 |
| Nygaardsgaten 32 AS | Real estate | 1986 |
| Nygaardsgt. 43 AS | Real estate | 2019 |
| Nygaardsgt. 7 AS | Households | 1938 |
| Nygaardsplassen AS | Real estate | 2017 |
| Nyggt Invest AS | Real estate | 2018 |
| Nær Arkitektur AS | Professional & scientific | 2024 |
| Næringseiendom AS | Real estate | 2022 |
| Næss Portefølje Da | Wholesale & retail | 2002 |
| Nöyd AS | Other services | 2019 |
| Nøklestad Bil AS | Wholesale & retail | 2018 |
| O Duenes & P Johannesen Ans | | 1994 |
| O-B Invest AS | Real estate | 2014 |
| O. D. Holding AS | Administrative & support | 2005 |
| O3M Eiendom AS | Real estate | 2007 |
| O3M Holding AS | Real estate | 2005 |
| Oasen Tannklinikk AS | Health & social care | 2018 |
| Object Generation AS | Information & communication | 2013 |
| Oc Gustavsen AS | | 2023 |
| Odds Konditori Og Bakeri AS | Manufacturing | 2002 |
| Odhuset AS | Wholesale & retail | 2021 |
| Odra Eiendom AS | Real estate | 2022 |
| Oe Kiropraktikk AS | Health & social care | 2022 |
| Oec AS | Professional & scientific | 2011 |
| Offisersporten AS | Real estate | 2020 |
| Ogre Holding AS | Financial services | 2014 |
| Ohn Montering AS | Construction | 2021 |
| Oiva Health Norway AS | Health & social care | 2024 |
| Oktav Reklamebyrå AS | Professional & scientific | 2019 |
| Ola Svendsen Eiendom AS | Real estate | 2013 |
| Olan Invest AS | Financial services | 2018 |
| Oldlin Eiendom AS | Real estate | 2025 |
| Ollivier Consulting AS | Professional & scientific | 2026 |
| Olsen Billakkering AS | Other services | 2000 |
| Olsen Glass AS | Manufacturing | 1985 |
| Olsun Holding AS | Manufacturing | 2022 |
| Omhu Skin Care AS | Wholesale & retail | 2021 |
| One Click Pulse AS | Information & communication | 2023 |
| One Pixel AS | | 2023 |
| Onstad Gruppen AS | Real estate | 2025 |
| Onstad Invest AS | Real estate | 1985 |
| Onsøy Båthavn AS | Transport & logistics | 1994 |
| Ophta AS | Wholesale & retail | 2021 |
| Optimus Personal AS | Professional & scientific | 2018 |
| Opus Invest AS | Real estate | 2000 |
| Ordinary AS | Real estate | 2019 |
| Ortopediskomakeren AS | Manufacturing | 1992 |
| Oryton AS | Information & communication | 2017 |