| M Bergli Holding AS | | 2025 |
| M Boligprosjekt AS | Real estate | 2026 |
| M Hatle AS | | 2025 |
| M Myhra Holding AS | | 2026 |
| Mabeso Holding AS | | 2025 |
| Magne Kvamen AS | Information & communication | 2015 |
| Magnussen Eiendomsutvikling AS | Real estate | 2013 |
| Magnussen Gulvsliping AS | Construction | 2015 |
| Maler Fredrik Olsson AS | Construction | 2015 |
| Malerfirma Gammelseter & Rikardsen AS | Construction | 2025 |
| Malinor AS | Administrative & support | 2025 |
| Maltkleiva 2 AS | Real estate | 2022 |
| Malune AS | Real estate | 2007 |
| Mam Holding AS | | 2026 |
| Mamma Italia AS | Hospitality | 2021 |
| Manacrm AS | Information & communication | 2026 |
| Mandal Vest AS | Real estate | 2007 |
| Mandt Holding AS | | 2019 |
| Manger Handelseiendom AS | Real estate | 2014 |
| Manna Rørservice AS | Construction | 2023 |
| Marcodor Eiendom AS | Real estate | 2006 |
| Maren Kvernmo Frisør AS | Other services | 2022 |
| Marex Ocean AS | Professional & scientific | 2025 |
| Marigaard AS | Real estate | 2005 |
| Maro Bygg AS | Construction | 2017 |
| Marq AS | Professional & scientific | 2019 |
| Mars AS | Real estate | 2012 |
| Marte Helen AS | Real estate | 2018 |
| Marte Lerberg Kopstad Invest AS | | 2020 |
| Martin Eriksen Transport AS | Transport & logistics | 2013 |
| Martin Johnsrud Holding AS | Real estate | 2012 |
| Martinsen Bilsalg AS | Wholesale & retail | 2025 |
| Masiva AS | Transport & logistics | 2024 |
| Mastedalsveien SA | Real estate | 1981 |
| Matematikk AS | Education | 2020 |
| Matijo Eiendom AS | Real estate | 2025 |
| MB Eiendom AS | Administrative & support | 2000 |
| MB Utvikling Da | Information & communication | 2005 |
| Mblaise AS | Information & communication | 2021 |
| MBR AS | Real estate | 2020 |
| Mcø Holding AS | Financial services | 2005 |
| Mdco Buskerud AS | Health & social care | 2010 |
| Me Management AS | Professional & scientific | 2017 |
| Mebyr AS | Construction | 1994 |
| Medhelp Innovation AS | Professional & scientific | 2022 |
| Mellerud Eiendomsutvikling AS | Manufacturing | 2005 |
| Mema Kjeveortopedi AS | Health & social care | 2013 |
| Mema Kjeveortopedi AS | Health & social care | 2026 |
| Menova Arbeid Og Inkludering AS | Health & social care | 2021 |
| Menova AS | Health & social care | 1992 |
| Menova Kommunale Tjenester AS | Health & social care | 2020 |
| Meoa Holding AS | | 2025 |
| Mer Innovasjon AS | Professional & scientific | 2011 |
| Merchant Brokers AS | Administrative & support | 2013 |
| Merit AS | Real estate | 1982 |
| Mesh Eiendom AS | Real estate | 2009 |
| Mess-El AS | Construction | 2025 |
| Metausage AS | Information & communication | 2026 |
| Meteoritten AS | Administrative & support | 2014 |
| MG Hønefoss AS | Wholesale & retail | 2008 |
| Mia's Choice AS | Wholesale & retail | 2021 |
| Mie & Modalen AS | Agriculture & fishing | 2009 |
| Miljø- Og Overflateservice AS | Administrative & support | 2018 |
| Minilager Ringerike AS | Transport & logistics | 2020 |
| Mira Handel AS | Wholesale & retail | 2017 |
| Miraskogen AS | Wholesale & retail | 2016 |
| Miro Invest AS | Real estate | 2010 |
| Mirza Holding AS | | 2019 |
| Mita Media AS | Information & communication | 2013 |
| ML Handel AS | Wholesale & retail | 2024 |
| Mo Drift AS | Real estate | 2017 |
| Mo Renhold Butikk AS | Wholesale & retail | 2023 |
| Mobile Hønefoss AS | Wholesale & retail | 2001 |
| Moda AS | Financial services | 2005 |
| Moha Invest AS | Wholesale & retail | 2009 |
| Moholdt AS | Real estate | 2016 |
| Molind Eiendom AS | Real estate | 2023 |
| Molind Holding AS | Construction | 2018 |
| Momarken Butikkeiendom AS | Real estate | 2015 |
| Mona Haug | Agriculture & fishing | 2013 |
| Mona Lisa Hair Fashion AS | Other services | 2006 |
| Mongstad Handelseiendom AS | Real estate | 2017 |
| Monn Aktiv AS | Administrative & support | 2013 |
| Moovo AS | Transport & logistics | 2025 |
| More Than One AS | Health & social care | 2018 |
| Mori Eiendomsutvikling AS | Real estate | 2013 |
| Morten Ellingsen - Tilgangskontroll I Sap AS | Information & communication | 2023 |
| Morten Engebretsen Holding AS | Construction | 2014 |
| Morud Invest AS | Financial services | 2005 |
| Mos Invest AS | Financial services | 2017 |
| Mosconi Norge AS | Construction | 2017 |
| Mosjøen Handelspark AS | Real estate | 2016 |
| Mosjøen Handelspark II AS | Real estate | 2017 |
| MP Truck Design AS | Wholesale & retail | 2025 |
| MS Art AS | Wholesale & retail | 2025 |
| MS Auto AS | Wholesale & retail | 2019 |
| MT Klima AS | Construction | 2018 |
| MTM Holdings AS | Wholesale & retail | 2023 |
| Muldico AS | Real estate | 2016 |
| Multi VVS & Varmepumper AS | Construction | 2023 |