| Lillemark Eiendom AS | Real estate | 2026 |
| Linden Invest AS | Real estate | 2010 |
| Lindseth Invest AS | Professional & scientific | 2007 |
| Lindseth Reklame AS | Professional & scientific | 1985 |
| Link Up Eiendom AS | Real estate | 2012 |
| Linnvasselv Kraftlag SA | Energy | 1959 |
| Liroy Da | Other services | 1991 |
| Lise Sofie AS | Health & social care | 2022 |
| LM Eiendom AS | Real estate | 2023 |
| LMH Eiendom AS | Real estate | 2024 |
| Local Logistics AS | Professional & scientific | 2022 |
| Lokalkalenderen AS | Professional & scientific | 2010 |
| Lost Highway Festival AS | Administrative & support | 2026 |
| Lunkan Eiendom AS | Real estate | 1998 |
| Lupa AS | Administrative & support | 2019 |
| Lusie Holding AS | | 2017 |
| Lutdal Eiendom AS | Real estate | 2005 |
| Lutdalgruppen AS | Wholesale & retail | 2005 |
| Lux Autostrada AS | Other services | 2025 |
| Lykkeland Steinkjer AS | Arts & recreation | 2014 |
| Lyng Invest AS | | 2026 |
| Lyngstad Arkitekter AS | Professional & scientific | 1999 |
| Lyngstad Eiendom AS | Real estate | 1988 |
| Lys & Glad AS | Real estate | 2003 |
| Lø Grendehus SA | Other services | 1992 |
| Lømsen Kro Og Gatekjøkken AS | Hospitality | 2011 |
| Lønnum Psykologtjenester AS | Health & social care | 2026 |
| Løsbergvegen 2 AS | Real estate | 2006 |
| Løv Studio AS | Other services | 2025 |
| M Seem Transport AS | Transport & logistics | 1987 |
| M-A Holding AS | | 2025 |
| M.K Utbygging AS | Real estate | 2020 |
| Magtech AS | Professional & scientific | 2001 |
| Maleboblen Ans | Arts & recreation | 2022 |
| Malerfirma Schei & Brandtzæg AS | Construction | 1997 |
| Malimo AS | Education | 2017 |
| Malimo AS | Education | 2024 |
| Malin AS | Hospitality | 2020 |
| Malmo Skog Og Utmarkstjenester AS | Agriculture & fishing | 2024 |
| Malmo Sport AS | Wholesale & retail | 1922 |
| Maluma AS | Professional & scientific | 2022 |
| Mane AS | | 2025 |
| Maras Steinkjer AS | Construction | 2014 |
| Marcos AS | Health & social care | 1995 |
| Mari Fiskvik Legekontor AS | Health & social care | 2014 |
| Marisletta Barnehage SA | Education | 1989 |
| Maritim Charter AS | Transport & logistics | 1987 |
| Maritimeauction.Eco AS | Information & communication | 2022 |
| Mark Up AS | Professional & scientific | 2019 |
| Marthe AS | | 2022 |
| Martinsen Enterprice AS | Other services | 2013 |
| Martinussen Invest AS | | 2026 |
| Matin AS | Hospitality | 2023 |
| Mats Erik Storstad AS | Agriculture & fishing | 2008 |
| Mattis Steinkjer AS | Wholesale & retail | 1993 |
| Mavo Holding AS | Information & communication | 2023 |
| Mavo Music AS | Information & communication | 2023 |
| Meda-Taxi Araya AS | Transport & logistics | 2024 |
| Medica Ink AS | Health & social care | 2025 |
| Medtek AS | Transport & logistics | 2014 |
| Medxplore AS | Professional & scientific | 2013 |
| Megatrykk AS | Professional & scientific | 2023 |
| Mejoso Holding AS | | 2013 |
| Mersalg & Marked AS | Wholesale & retail | 2021 |
| Metall Bygg AS | Construction | 2009 |
| Metall Bygg Holding AS | Construction | 2023 |
| MH Consult AS | Professional & scientific | 2006 |
| Midt-Norsk Arrangements Service Da | Administrative & support | 1997 |
| Midt-Norsk Blomsterengfrø Ans | Agriculture & fishing | 1994 |
| Midt-Norsk Eiendom Holding AS | Real estate | 2004 |
| Midt-Norsk Murservice AS | Construction | 2026 |
| Midtrans AS | Transport & logistics | 2012 |
| Miljøbyen Mære AS | Real estate | 2020 |
| Mimir Analytics AS | Information & communication | 2018 |
| Mindbusiness AS | Professional & scientific | 2006 |
| Mintage Eiendom AS | Real estate | 2025 |
| Mintage Holding AS | | 2012 |
| Mintage Sushi Steinkjer AS | Hospitality | 2025 |
| Minto Consulting AS | Information & communication | 2005 |
| Mission Capital RL II AS | Real estate | 2019 |
| Miwi AS | Health & social care | 2024 |
| Miwi Holding AS | Other services | 2024 |
| Molovegen 12 Steinkjer AS | Other services | 2019 |
| Momic Invest AS | Financial services | 2015 |
| Monto AS | Construction | 2019 |
| Morten Ressem Holding AS | | 2026 |
| Mostinfo AS | Professional & scientific | 2020 |
| Motus Aktivitet AS | Education | 2013 |
| Moxness AS | | 2008 |
| MPJ Invest AS | | 2026 |
| MPM Service AS | Construction | 2009 |
| MR Byggvask AS | Administrative & support | 2022 |
| Muba Invest AS | | 2015 |
| Multibygg Solutions AS | Construction | 2013 |
| Murmester Ketil Hansen AS | Construction | 1994 |
| Murmester Magnus Hagen AS | Construction | 2015 |
| Mux Holding AS | | 2026 |
| Myrslo Skogavvirkning AS | Agriculture & fishing | 1987 |
| Myrvangberget Samdrift Da | Agriculture & fishing | 2003 |
| Mytlagard Samdrift Da | Agriculture & fishing | 2007 |