| Møbelringen Steinkjer AS | Wholesale & retail | 1997 |
| Møller-Belbo AS | | 2025 |
| Møslag SA | Wholesale & retail | 2018 |
| Namdal Bobilutleie AS | Administrative & support | 2016 |
| Nautecoria AS | Transport & logistics | 2026 |
| New China House AS | Hospitality | 2020 |
| Niliv AS | Construction | 2021 |
| NMV1 AS | Real estate | 2005 |
| Noen AS | Health & social care | 2006 |
| Nor Marina AS | Real estate | 2000 |
| Nord - Auto Import AS | Wholesale & retail | 2014 |
| Nord Regnskap AS | | 2020 |
| Nord Taxi AS | Transport & logistics | 2025 |
| Nord-Trøndelag Eiendom AS | Real estate | 2017 |
| Nord-Trøndelag Eiendom II AS | Real estate | 2019 |
| Nord-Trøndelag Elektrisitetsverk AS | Energy | 2008 |
| Nordavind Energi Finnmark AS | | 2024 |
| Nordavind Energi Trøndelag AS | Energy | 2025 |
| Nordsia Eiendom AS | Real estate | 1961 |
| Nordsihaugen Familiebarnehage AS | Education | 2006 |
| Nordvegr AS | Professional & scientific | 2023 |
| Norsk Landbrukstakst SA | Other services | 2018 |
| Norsk Transformator AS | Manufacturing | 2007 |
| Norsk Transformator Beredskap AS | Wholesale & retail | 2010 |
| Northspace AS | Information & communication | 2026 |
| Nortrafo AS | Manufacturing | 2019 |
| Nortrafo Production AS | Manufacturing | 2020 |
| Norum Utbygging AS | Financial services | 2016 |
| Norvegen Group AS | Administrative & support | 2021 |
| Norwegian Knitting AS | Professional & scientific | 2020 |
| Nostradamus AS | | 2025 |
| Notramo AS | Real estate | 2002 |
| Notramo II AS | Real estate | 2006 |
| Notramo III AS | Real estate | 2019 |
| Nova Frisør AS | Other services | 1999 |
| NS Betong AS | Construction | 2023 |
| NT Last Og Buss AS | Other services | 2005 |
| Nte Energi AS | Energy | 2005 |
| Nte Havvind AS | | 2023 |
| Nte Havvind Holdco AS | | 2023 |
| Nte Hydrogen AS | Manufacturing | 2016 |
| Nte Marked AS | Energy | 2007 |
| Nte Montenegro AS | Energy | 2010 |
| Nte Nordavind Energi AS | | 2025 |
| Nte Nærvarme AS | Professional & scientific | 2023 |
| Nte Solkraft AS | Energy | 2020 |
| Nte Telekom AS | Information & communication | 2021 |
| Nte Vindkraft AS | | 2023 |
| Null Stress Bygg AS | Construction | 2024 |
| Nye Chriss Eiendom AS | Other services | 1989 |
| Nye Reitanfeltet Samdrift Da | Agriculture & fishing | 2007 |
| Nyrø Gård Da | | 2024 |
| O Norum Eiendom AS | Real estate | 1990 |
| Oah Barne- Og Familie Støtte AS | Health & social care | 2023 |
| Odd Einar Kne AS | Construction | 1995 |
| Odd Gunnar Ås Bjørk AS | Professional & scientific | 2012 |
| Odd Jørgen Rye Invest AS | Real estate | 1996 |
| Og Holding AS | Real estate | 2017 |
| Ogna Grunneierlag SA | Real estate | 2017 |
| Ogndal Tildelingsområde SA | Agriculture & fishing | 2023 |
| Ogndalkjøtt Eiendom Da | Real estate | 2005 |
| Ogndalsvegen 11 Steinkjer AS | Wholesale & retail | 2014 |
| Ogndalsvegen 143 AS | Real estate | 2025 |
| Ogndalsvegen 16 AS | Real estate | 2020 |
| Okkenhaugveien 8 AS | Real estate | 2021 |
| Oks Trøndelag SA | Education | 1996 |
| Oksefjorden Vindkraftverk AS | Professional & scientific | 2023 |
| Oksås AS | | 2014 |
| Ola Benan AS | Professional & scientific | 2015 |
| Ola Huseth AS | Information & communication | 2025 |
| Olg Eiendom AS | Real estate | 2020 |
| Omli Maskin AS | Agriculture & fishing | 2013 |
| Omsorgstjeneste Steinkjer AS | Health & social care | 2025 |
| Ondego AS | Construction | 2019 |
| Online 24 AS | Information & communication | 2008 |
| Online 24 Ikt AS | Information & communication | 2017 |
| Online Fitness Quality AS | Information & communication | 2023 |
| Opheim Utbygging AS | Construction | 2012 |
| Or-Nesset AS | Construction | 2014 |
| Orion Pizzagrill AS | Hospitality | 2013 |
| Orkel Biox AS | Manufacturing | 2024 |
| Otto Sverdrup Eiendom AS | Real estate | 2006 |
| Otto Ulseth AS | Professional & scientific | 2025 |
| OV18 Kultur AS | Education | 2022 |
| Overrein AS | | 2004 |
| Ox Grill AS | Hospitality | 2024 |
| P. R. Lunkan Transport AS | Transport & logistics | 1995 |
| Palermo Steinkjer AS | Hospitality | 2020 |
| Papyria Holding AS | Information & communication | 2025 |
| Pedersen Og Lyngved Multiservice Ans | Manufacturing | 2022 |
| Penniless Technologies AS | Information & communication | 2020 |
| Pentru Tine Nuf | Hospitality | 2017 |
| Per Odd Austad A/S | Construction | 1988 |
| Per Odd Salberg AS | Financial services | 2005 |
| Peteca AS | Other services | 2026 |
| Peter Øiens Utvikling AS | Real estate | 2012 |
| PLG Eiendom AS | Real estate | 2019 |
| PLG Holding AS | Professional & scientific | 1986 |
| Plte Eiendom AS | Real estate | 2011 |
| PM Holding AS | Real estate | 2012 |