| Mkarlsen Holding AS | | 2021 |
| MM Eiendomsconsult AS | Real estate | 1991 |
| Mobil Telemarketing AS | Administrative & support | 2024 |
| Mobiledisplay AS | Transport & logistics | 2002 |
| Mobility Vestfold AS | Information & communication | 2022 |
| Mobilmarked AS | Other services | 2021 |
| Mobilverkstedet AS | Other services | 2016 |
| Mobø AS | Real estate | 2001 |
| Modalen Invest AS | | 1993 |
| Modbus Holding AS | | 2025 |
| Modin Invest AS | | 2024 |
| Modulera AS | Construction | 2019 |
| Moe Capital Group AS | | 2026 |
| Moen Investment AS | | 2019 |
| Moer Sandefjord AS | Construction | 1984 |
| Mokollen Barnehage AS | Education | 1993 |
| Mokollen Eiendom AS | Real estate | 2008 |
| Momenti AS | Wholesale & retail | 2016 |
| Mondeo Eiendom AS | Real estate | 2014 |
| Mondesir AS | Professional & scientific | 2005 |
| Montana AS | Real estate | 2012 |
| Montasjemateriell AS | Wholesale & retail | 2024 |
| Monte Cristo Invest AS | Real estate | 2023 |
| Moon Pool Holdings AS | | 2021 |
| Moonsoft AS | Information & communication | 2015 |
| Mordal AS | Financial services | 2005 |
| Morild Film AS | Information & communication | 2021 |
| Morozov AS | Financial services | 1992 |
| Morsei & Bestis AS | Real estate | 2013 |
| Morsomt Navn Holding AS | Wholesale & retail | 2012 |
| Morten Berg Transport AS | Transport & logistics | 2018 |
| Morten Langeli Holding AS | | 2025 |
| Morten Mathisen Holding AS | | 2006 |
| Mosjøen Prosjekt AS | Real estate | 2010 |
| Motema AS | | 2019 |
| Motorx AS | Wholesale & retail | 2026 |
| Movita AS | Health & social care | 2026 |
| Mpowerstation AS | Information & communication | 2023 |
| MRC AS | Health & social care | 2023 |
| MS Maler Firma AS | Construction | 2020 |
| MT Lystad Invest AS | | 2020 |
| Muchoniceness AS | Information & communication | 2019 |
| Muh Invest AS | Health & social care | 2025 |
| Multicase Norge AS | Information & communication | 1996 |
| Multivac | Professional & scientific | 2010 |
| Multivac Aktiebolag | Administrative & support | 2019 |
| Multivac AS | Wholesale & retail | 1988 |
| Munera AS | Real estate | 2014 |
| Mur Og Bygg Sandefjord AS | Construction | 2011 |
| Murerfirma Bjelland AS | Construction | 2012 |
| Murmester Oddvar Johannessen AS | Construction | 2011 |
| Murmester Riis Invest AS | | 2016 |
| Murmester Tor Michelsen AS | Construction | 1989 |
| Murmester Åge Leth AS | Construction | 2011 |
| Museumsgata 4 AS | Real estate | 2018 |
| Museumsgata 6A AS | Real estate | 2018 |
| Museumsgata 6B AS | Real estate | 2018 |
| Museumsgaten 43 AS | Real estate | 1997 |
| Mushroom AS | Wholesale & retail | 2021 |
| MV Studio AS | Other services | 2017 |
| My Pit Stop AS | Hospitality | 2026 |
| Myholding AS | | 2022 |
| Myhremaskin AS | Administrative & support | 2017 |
| Mym Transport AS | Transport & logistics | 2025 |
| Myrobert AS | Information & communication | 2026 |
| Myrvang Consulting AS | Professional & scientific | 2019 |
| Mytrinity AS | Information & communication | 2022 |
| Måteholdsforeningen AS | Wholesale & retail | 2023 |
| Mö Scandinavia AS | Wholesale & retail | 2021 |
| Møbelringen Sandefjord AS | Wholesale & retail | 2006 |
| Mølen AS | Real estate | 2005 |
| Mølleloftet Bakeri AS | Manufacturing | 2026 |
| Møller Og Petersen Eiendom AS | Real estate | 2021 |
| Mønnerødveien 1 AS | Manufacturing | 2014 |
| Mørk & Petersen AS | Professional & scientific | 2024 |
| Mørk-Andersen Holding AS | | 2021 |
| N.V.G AS | Wholesale & retail | 2018 |
| Nalum Holding AS | Construction | 2022 |
| Nansen Camp AS | Arts & recreation | 2018 |
| Naprapat Og Helse AS | Health & social care | 2022 |
| Naprapat Og Helse Holding AS | Health & social care | 2022 |
| Naranmo AS | Real estate | 2000 |
| Natholmen Brygge AS | Transport & logistics | 2005 |
| Natholmsundets Flytebrygge SA | Arts & recreation | 1974 |
| Naturlighet AS | Agriculture & fishing | 2023 |
| Natvall Eiendom AS | Real estate | 1987 |
| Natvall Invest AS | Real estate | 2005 |
| Navigator Amon Shipping AS | Transport & logistics | 2025 |
| Navigator Amundsen AS | Transport & logistics | 2024 |
| Navigator Archer AS | Transport & logistics | 2024 |
| Navigator Norway AS | Wholesale & retail | 2013 |
| NBT Anlegg AS | Construction | 1991 |
| Nedre Gokstad Bolig AS | Real estate | 2026 |
| Nedre Gokstad Gård AS | Real estate | 2013 |
| Nedre Gokstadvei 25 AS | Real estate | 2015 |
| Nedre Langgate 19 AS | Real estate | 2005 |
| Nedre Langgate 37 AS | Real estate | 1967 |
| Nedre Langgate 41 AS | Real estate | 2007 |
| Nedre Åsenvei Panorama AS | Real estate | 2016 |
| Neev AS | Education | 2022 |