| Marit Thomassen Holding AS | | 2022 |
| Marius Kjeldahl AS | Information & communication | 2006 |
| Marmag AS | Financial services | 2017 |
| Marylebone AS | Financial services | 2018 |
| Masiw Holding AS | Real estate | 2014 |
| Massimo Pizza AS | Hospitality | 2022 |
| Masvale AS | Financial services | 2018 |
| Matchless Living AS | Wholesale & retail | 2020 |
| Matina Invest AS | Real estate | 1998 |
| Matiso Invest AS | | 2023 |
| Maturigo AS | Health & social care | 2012 |
| Mawaro Invest AS | | 2017 |
| Max Aasbø Holding AS | | 2022 |
| Mayapapaya AS | Professional & scientific | 2019 |
| Mazut AS | Education | 2017 |
| Mazut Lindebergveien AS | | 2020 |
| Mazut Oslo AS | Education | 1995 |
| MBV Holding AS | Administrative & support | 2017 |
| Me Capital AS | Financial services | 2016 |
| Melvin Eiesland AS | Real estate | 2008 |
| Mesa 22 AS | Real estate | 2010 |
| Mesan AS | | 2019 |
| MFM Bygg AS | Construction | 2021 |
| MHJ Holding AS | | 2022 |
| Miasol AS | | 2015 |
| MILLIMETER1 AS | Professional & scientific | 2025 |
| Mimo Interiørarkitektur AS | Professional & scientific | 2015 |
| Minothi AS | Education | 2016 |
| Mirima AS | Professional & scientific | 2014 |
| Mmem Invest AS | | 2024 |
| MMK Invest AS | | 2013 |
| Modell Marine AS | Transport & logistics | 2025 |
| Modes AS | Professional & scientific | 2025 |
| Moir Invest AS | | 2024 |
| Momsen Holding AS | | 2021 |
| Montana Invest AS | | 2024 |
| Mortem AS | Information & communication | 2022 |
| Morten Hippe Holding AS | Financial services | 2016 |
| Mortensen Dental AS | Manufacturing | 2011 |
| Morud Holding AS | Financial services | 2014 |
| Mossi AS | | 2025 |
| Mossi Invest AS | | 2025 |
| Motion Oslo AS | Wholesale & retail | 2021 |
| Mov Consulting AS | Professional & scientific | 2019 |
| MR Holiding AS | Information & communication | 2023 |
| MT Olympus AS | Professional & scientific | 2014 |
| Muto AS | Professional & scientific | 2025 |
| MWT Invest AS | | 2021 |
| Myst Norge AS | Wholesale & retail | 2025 |
| Møfø Holding AS | | 2022 |
| Mølle Invest AS | Real estate | 2008 |
| Nabele AS | | 2023 |
| Namdalen Invest AS | | 2022 |
| Naviare AS | Financial services | 2005 |
| Nea 1 AS | Financial services | 2017 |
| Negaard Holding AS | Real estate | 2012 |
| Neglbutikk AS | Other services | 2024 |
| Nemeet AS | Professional & scientific | 2012 |
| Nen Holding AS | | 2022 |
| Nesset Film AS | Information & communication | 2014 |
| Netteiendom AS | Professional & scientific | 2001 |
| Nettsidebedrift AS | Information & communication | 2025 |
| Neven AS | Financial services | 2004 |
| NG Invest AS | Financial services | 2005 |
| Nida Kapital AS | | 2026 |
| Nikola AS | | 2019 |
| Nilima Invest AS | | 2025 |
| Nils & Ronny AS | Information & communication | 2012 |
| Niphi AS | Financial services | 2005 |
| NL Invest Utleie AS | Real estate | 2022 |
| Nobels Invest AS | | 2019 |
| Nomi Holding AS | Financial services | 2015 |
| Noorse Oost-Indische Compagnie Nuf | Professional & scientific | 2009 |
| Nor Godt AS | Wholesale & retail | 1993 |
| Norak AS | | 2011 |
| Norcard Services AS | Professional & scientific | 2011 |
| Nordic Helicopter Support AS | Transport & logistics | 2017 |
| Nordic Symbol Yachts Ltd Nuf | Wholesale & retail | 2007 |
| Norsk Eiendomsutvikling AS | Real estate | 1998 |
| Norsk Gulvservice AS | Construction | 2011 |
| Norsk Importagentur AS | Wholesale & retail | 2023 |
| Norsk Kapital AS | Professional & scientific | 1991 |
| Norstead AS | Manufacturing | 2023 |
| Norstock AS | Professional & scientific | 2026 |
| Norway Does Productions AS | Information & communication | 2018 |
| Notto Eiendom AS | Real estate | 1982 |
| NP Racing AS | Arts & recreation | 2009 |
| Nutcracker Solutions AS | Professional & scientific | 2012 |
| Nuviou AS | Professional & scientific | 2025 |
| Nybyen Prosjekt AS | Real estate | 2017 |
| Nyera Eiendom AS | Real estate | 2024 |
| Nåli AS | Manufacturing | 2026 |
| Næringsweb AS | Information & communication | 1996 |
| O. Bjørknes Holding AS | Professional & scientific | 2020 |
| Oddegull AS | Wholesale & retail | 1997 |
| Odexer AS | Professional & scientific | 2008 |
| Odin Glow AS | Professional & scientific | 2025 |
| Ohc Arkitektur & Design AS | Professional & scientific | 2001 |
| Ohc Bygg AS | Real estate | 2001 |
| Ohc Holding AS | Real estate | 2005 |