| Maks Underholdning AS | Administrative & support | 2025 |
| Malde Invest AS | Financial services | 2005 |
| Malde Invest I AS | | 2018 |
| Maler Arild Njærheim AS | Construction | 1992 |
| Maler Holding AS | Construction | 2015 |
| Malerfirma Odd Fløysvik AS | Construction | 2021 |
| Malermester K. Meyer AS | Construction | 2009 |
| Malermester T. Armstrong AS | Construction | 2020 |
| Malitho AS | | 2020 |
| Malmheim Holding AS | Real estate | 2013 |
| Malmin & Co AS | | 2026 |
| Malmin Eiendom AS | Real estate | 2013 |
| Malmin Entreprenør AS | Construction | 2014 |
| Malmin Holding AS | | 2020 |
| Mama Holdco AS | Administrative & support | 2019 |
| Mama Thai Mat AS | Hospitality | 2023 |
| Mamema Invest AS | Financial services | 2011 |
| Mamfr Investment AS | Professional & scientific | 2023 |
| Mamfr Regnskap AS | Professional & scientific | 2023 |
| Mammamestring AS | Education | 2025 |
| Mammut Invest AS | | 2021 |
| Mamori Eiendom AS | Real estate | 2014 |
| Mandal Offentlig Eiendom AS | Real estate | 2022 |
| Mane Contract Services Limited | Administrative & support | 2012 |
| Mangersnes Holding AS | Real estate | 2010 |
| Mannes Holding AS | Financial services | 2018 |
| Manuellterapeut Fredrik Kristoffersen AS | Health & social care | 2019 |
| Manvir AS | Hospitality | 2026 |
| Maph Holding AS | Other services | 2024 |
| Mapsi AS | Information & communication | 2006 |
| Marching on Together AS | | 2021 |
| Marcon AS | Professional & scientific | 1992 |
| Maren Invest AS | Financial services | 2005 |
| Marfh Holding AS | | 2020 |
| Mari Invest AS | | 2022 |
| Maringto AS | | 2007 |
| Marinius Handel AS | Wholesale & retail | 2021 |
| Marino AS | Information & communication | 2024 |
| Marinteq AS | Information & communication | 2026 |
| Marit Assets AS | Financial services | 2006 |
| Maritime Digital Solutions AS | Information & communication | 2024 |
| Marius AS | Real estate | 1997 |
| Mariusegg Holding AS | | 2025 |
| Mariva Holding AS | | 2020 |
| Markageilen Samdrift Da | Agriculture & fishing | 2001 |
| Marlon Holding AS | Construction | 2020 |
| Marnarkrysset AS | Real estate | 2014 |
| Marsol Invest AS | | 2026 |
| Marte Invest AS | | 2020 |
| Martec Invest AS | | 2019 |
| Martin Berg Mat AS | Wholesale & retail | 2025 |
| Martin Berge Holding AS | Real estate | 2016 |
| Martinsen AS | Wholesale & retail | 1996 |
| Marton Rideutstyr AS | Wholesale & retail | 2022 |
| Martrans Norway AS | Transport & logistics | 2017 |
| Marwell AS | Wholesale & retail | 2019 |
| Marwell Holding AS | Wholesale & retail | 2021 |
| Marwell Products AS | Professional & scientific | 2021 |
| Mas Finans AS | | 2025 |
| Masa Eiendom AS | Real estate | 2006 |
| Masg Holding AS | | 2025 |
| Maskin & Auto Service AS | Other services | 1988 |
| Maskincompaniet AS | Wholesale & retail | 2005 |
| Massive Dynamics AS | Real estate | 2013 |
| Master Proff Bygg AS | Construction | 2022 |
| Mastergruppen AS | Transport & logistics | 2022 |
| Mat Og Trening Sandnes AS | Education | 2024 |
| Matfylket Rogaland AS | Transport & logistics | 2019 |
| Matkurv AS | Wholesale & retail | 2026 |
| Matværket AS | Hospitality | 2011 |
| Mau Invest AS | | 2023 |
| Mauryn AS | Information & communication | 2024 |
| Max Elija AS | Professional & scientific | 2021 |
| Max-It AS | Information & communication | 2019 |
| Maxi Fysioterapi AS | Health & social care | 2018 |
| Maxi Tannhelse AS | Health & social care | 2017 |
| Maxi Velvære AS | Other services | 2021 |
| Maïa AS | | 2020 |
| MB Maskin AS | Construction | 2011 |
| MC Lea AS | Wholesale & retail | 1999 |
| MC Utstyr AS | Wholesale & retail | 2022 |
| Mc-Utstyr Bergen AS | Wholesale & retail | 2021 |
| Mccardle Invest AS | Professional & scientific | 2025 |
| Mccardle Recruitment Services AS | Administrative & support | 2017 |
| MCS Kenny International (U.K) Limited | Administrative & support | 2010 |
| MD Auto AS | Wholesale & retail | 2025 |
| MD Bystasjonen AS | Other services | 2014 |
| Mde Holding AS | | 2018 |
| Me Fikse Maden AS | Hospitality | 2024 |
| Mea Auto AS | Wholesale & retail | 2026 |
| Mech Tronic Ans | Wholesale & retail | 2004 |
| Mechanical Solutions AS | Manufacturing | 2022 |
| Mechtronic AS | Manufacturing | 2009 |
| Medco Dinhms Forus AS | Health & social care | 2006 |
| Medea Technologies AS | Information & communication | 2005 |
| Medgang Invest AS | | 2025 |
| Media Lab Da | Information & communication | 2005 |
| Mediteam AS | Health & social care | 1995 |
| Medpalett AS | Manufacturing | 2004 |
| Medtek Ki AS | Information & communication | 2026 |