| M by Eijk AS | Information & communication | 2026 |
| M Holmgren Eiendom AS | Real estate | 2023 |
| M Thomassen Holding AS | Real estate | 2012 |
| M&B Holding AS | | 2026 |
| M-Trax AS | Professional & scientific | 2018 |
| M.Heggelund Holding AS | | 2025 |
| M.M. Sara Holding AS | Transport & logistics | 2023 |
| M.M. Sara Transport AS | Transport & logistics | 2008 |
| M.Nuth Pedersen Holding AS | | 2021 |
| M.Olsen Holding AS | Construction | 2020 |
| M.Witte AS | Hospitality | 2026 |
| M2 Utbygging AS | Real estate | 2005 |
| Ma-Bygg AS | Construction | 2026 |
| Mactta Helse AS | Health & social care | 2012 |
| Madssen Invest AS | Financial services | 2005 |
| Maffeis Engineering Norge AS | Professional & scientific | 2019 |
| Magasin Nord AS | Wholesale & retail | 1997 |
| Magne Investering AS | | 2011 |
| Magnus Maisenhølder AS | Professional & scientific | 2021 |
| Magnus Pettersen AS | Construction | 2023 |
| Maj-Lis Tangen Holding AS | | 2026 |
| Majala AS | Real estate | 2011 |
| Mannsverk Eiendom AS | Financial services | 2018 |
| Manuell Terapi Alta AS | Health & social care | 2004 |
| Manuell Terapi Eiendom AS | Real estate | 1995 |
| Maribo Holding AS | Financial services | 2016 |
| Marine Og Anleggservice AS | Manufacturing | 2025 |
| Marita Holding AS | | 2022 |
| Mark Eiendom AS | Real estate | 2003 |
| Markedsgata 14 AS | Real estate | 2015 |
| Markedsgata 18 AS | Real estate | 2020 |
| Markveien 14 AS | Real estate | 1999 |
| Markveien 2 AS | Real estate | 2018 |
| Markveien 39 AS | Real estate | 2022 |
| Markveien 39 Eiendom AS | Real estate | 2025 |
| Markveien 51 AS | | 2025 |
| Markveien 53 Alta AS | Real estate | 2020 |
| Markveien 55 Eiendom AS | Real estate | 2020 |
| Markveien Bygg AS | | 1986 |
| MARKVEIEN-48 AS | Real estate | 2015 |
| Martine AS | Other services | 2023 |
| Marzello AS | Wholesale & retail | 2026 |
| Maskin Service Nord AS | Manufacturing | 2024 |
| Maskin Support AS | Manufacturing | 2026 |
| Masvik Holding AS | | 2021 |
| Mathisen & Co Eiendom AS | Real estate | 1997 |
| Mathisens Landbruksservice AS | Wholesale & retail | 2007 |
| Mathisskogen AS | Construction | 2023 |
| Matium AS | | 2026 |
| Maurveien 14 AS | Real estate | 2018 |
| Maurveien 3 Alta AS | Real estate | 2023 |
| Maurveien 7 Alta AS | Real estate | 2021 |
| Mavi Eiendom AS | Real estate | 2018 |
| Mbellika AS | Professional & scientific | 2022 |
| Mcn-Holding AS | Real estate | 2023 |
| MCT Invest AS | | 2020 |
| Medfart AS | | 2022 |
| Mediaveien AS | Professional & scientific | 2018 |
| Medicum Utvikling AS | Real estate | 2013 |
| Medjo AS | Administrative & support | 2015 |
| Medjo Eiendom AS | Real estate | 2019 |
| Meieriveien 2 AS | Real estate | 2021 |
| Meieriveien 3 AS | Real estate | 2020 |
| Mek Holder AS | | 2022 |
| Mel Holding AS | Real estate | 2015 |
| Mellatronikk AS | Construction | 2017 |
| Mellatronikk AS | Construction | 2026 |
| Merhe AS | Wholesale & retail | 2026 |
| Merk Holdning AS | Real estate | 2017 |
| Merk Maten AS | Professional & scientific | 2017 |
| Merknorge AS | Professional & scientific | 2012 |
| Metarek AS | Wholesale & retail | 2005 |
| MH Tre & Laft AS | Agriculture & fishing | 2023 |
| Mhansen Holding AS | | 2025 |
| MHT Holding AS | | 2025 |
| Midt City Cafe AS | Hospitality | 2013 |
| Miho Film AS | Information & communication | 2008 |
| Mikkeli AS | Hospitality | 2015 |
| Mikkeli Eiendom AS | Real estate | 2014 |
| Mikkelsby Invest AS | | 2023 |
| Mikkelsen Holding AS | | 2014 |
| Milano Grill Og Pizza AS | Wholesale & retail | 2017 |
| Miljøsanering Nord AS | Construction | 2021 |
| Miljøteknikk Holding AS | Construction | 2019 |
| Miltrad AS | Wholesale & retail | 1999 |
| Mimåsa Hospitality AS | | 2020 |
| Mio Restaurant AS | Hospitality | 2015 |
| Mitt Lager AS | Real estate | 2022 |
| MJP Holding AS | Financial services | 2017 |
| Mjøen Holding AS | | 2024 |
| MK Johansen Drift AS | Professional & scientific | 2025 |
| MK Johansen Holding AS | Professional & scientific | 2021 |
| Mkristiansen Holding AS | Real estate | 2022 |
| MLS Fritid AS | Wholesale & retail | 2022 |
| MLS Holding AS | Wholesale & retail | 2022 |
| MLS Skillemoen AS | Real estate | 2022 |
| Mnbredal Holding AS | | 2023 |
| Monik Regnskap AS | Professional & scientific | 1999 |
| Montana Alta AS | Wholesale & retail | 2000 |
| Mool Holding AS | | 2023 |