| Milenkovic IT Invest AS | Information & communication | 2016 |
| Miljø Service Nuf | Administrative & support | 2014 |
| Miljøgass AS | Wholesale & retail | 2022 |
| Miljøgården AS | Construction | 2021 |
| Miljøpall Drammen AS | Wholesale & retail | 2023 |
| Miljøteknikk AS | Construction | 1999 |
| Miljøvann AS | Wholesale & retail | 1989 |
| Milksheik AS | Hospitality | 2024 |
| Milman AS | Health & social care | 2022 |
| Milman Tolk AS | Professional & scientific | 2026 |
| Min Fullmakt AS | Information & communication | 2026 |
| Minikran Øst AS | Administrative & support | 2025 |
| Minitopia Norge AS | Health & social care | 2025 |
| Minken Næringspark 2 AS | Real estate | 2009 |
| Mint Vask AS | Administrative & support | 2023 |
| Miocon AS | Information & communication | 2019 |
| Mirasierra AS | Real estate | 2005 |
| Missmaya AS | Wholesale & retail | 2015 |
| Mistel Park AS | Real estate | 2018 |
| Mistelpark B1 AS | Real estate | 2019 |
| Mistelpark B2 AS | Real estate | 2022 |
| Mistelpark B3 AS | Real estate | 2024 |
| Mistelpark Tomt AS | Real estate | 2020 |
| Mitchell Drift AS | Administrative & support | 2019 |
| MJM International AS | Wholesale & retail | 2005 |
| Mjølner Bygg Drammen AS | Real estate | 2017 |
| Mjøndalen Industries AS | | 2021 |
| Mjøndalen Transport 1 AS | Transport & logistics | 2026 |
| MK 27-29 Invest AS | | 2021 |
| MK Digital Regnskap Og Lønn AS | Professional & scientific | 2024 |
| MK Ix AS | | 2021 |
| ML Invest AS | Real estate | 2022 |
| ML Nordic AS | Wholesale & retail | 2022 |
| MLT & Gjengen AS | | 2020 |
| MM Tannlegeklinikk AS | Health & social care | 2016 |
| Mma Holding AS | | 2018 |
| MMK Blikk AS | Construction | 2020 |
| MMK Utleie AS | Administrative & support | 2018 |
| Mmmk Holding AS | Real estate | 2015 |
| MN Rørleggerbedrift AS | Construction | 2021 |
| Mnok Invest AS | Information & communication | 2023 |
| Mo Investering AS | | 2023 |
| Mo-Ny AS | Financial services | 2018 |
| Moai AS | Hospitality | 2024 |
| Mobil Og IT Drammen AS | Information & communication | 1964 |
| Mobile Doctor AS | Real estate | 2023 |
| Mobile Drammen AS | Other services | 1986 |
| Mocom AS | Wholesale & retail | 1992 |
| Moderne Hytter AS | Real estate | 2016 |
| Modulbygg Miljø AS | Construction | 2020 |
| Modultre AS | Construction | 2016 |
| Modum Glassindustri Eiendom AS | Real estate | 2008 |
| Moen & Ekeberg Ans | Construction | 1988 |
| Moen Bolig AS | Real estate | 2017 |
| Moen Bolig Prosjekt AS | Real estate | 2026 |
| Moen Enlien Invest AS | Administrative & support | 2012 |
| Mofo Holding AS | Wholesale & retail | 2021 |
| Mogensen Holding AS | | 2022 |
| Moi Trailer Nuf | Wholesale & retail | 2022 |
| Moker AS | Hospitality | 2025 |
| Moliti AS | Real estate | 2004 |
| Molu AS | Administrative & support | 2017 |
| Moment Invest AS | | 2023 |
| Momento Investering AS | | 2018 |
| Mona Lamm-Kittelsen AS | Financial services | 2005 |
| Monet Autospa AS | Other services | 2025 |
| Monika Tveit Holding AS | | 2021 |
| Monofokus AS | Information & communication | 2023 |
| Montesilva Eiendom AS | Real estate | 2017 |
| Montis Nordic AS | Construction | 2017 |
| Moods Frisør AS | Other services | 2021 |
| Moonlight Creative Solutions AS | Information & communication | 2024 |
| Moonlight Records Ans | | 1995 |
| Mooring Drammen AS | Transport & logistics | 2014 |
| Moov AS | Arts & recreation | 2008 |
| Moply Holding AS | Administrative & support | 2025 |
| Morcas AS | Professional & scientific | 2004 |
| Morgenbris AS | | 2024 |
| Morhof Holding AS | Construction | 2021 |
| Morkgruppen AS | Administrative & support | 2016 |
| Morten Brekke Holding AS | Real estate | 2006 |
| Morten F. Thomsen AS | Wholesale & retail | 2005 |
| Morten Johanson Spesialistpraksis I Nevrologi AS | Health & social care | 2020 |
| Morten Lysthaug AS | Wholesale & retail | 2008 |
| Mosaikk Reklame AS | Professional & scientific | 2005 |
| Most of All AS | Wholesale & retail | 2016 |
| Mota Invest AS | Wholesale & retail | 2021 |
| Motor Data AS | Information & communication | 1997 |
| Motor Forum AS | Wholesale & retail | 2010 |
| Motor Part AS | Wholesale & retail | 1982 |
| Motortransport AS | Transport & logistics | 2003 |
| Motto Holding AS | Wholesale & retail | 2010 |
| Motzfeldt Holding AS | | 2003 |
| Motzfeldt Regnskap AS | Professional & scientific | 2012 |
| Mouchri AS | Real estate | 2022 |
| Move-It AS | Manufacturing | 2022 |
| MP Bil AS | Wholesale & retail | 2024 |
| MP Holdco AS | | 2025 |
| MP Maskinservice Og Transport AS | Manufacturing | 2020 |
| MP Retail AS | Wholesale & retail | 2026 |