| Manta Ray AS | | 2024 |
| Manta Technologies AS | Information & communication | 2023 |
| Mante Kvedare AS | | 2019 |
| Mantec AS | Professional & scientific | 1998 |
| Mantena AS | Manufacturing | 2001 |
| Manthey Kula AS | Professional & scientific | 2014 |
| Mantle AS | Information & communication | 2012 |
| Mantle No AS | Professional & scientific | 2021 |
| Manto Norge AS | Wholesale & retail | 2026 |
| Manu Forti AS | Real estate | 2021 |
| Manuel Holding AS | | 2020 |
| Manuellterapiklinikken Brynseng SA | Health & social care | 2008 |
| Manufacture Oslo AS | Professional & scientific | 2020 |
| Manuscript AS | Information & communication | 2026 |
| Manushjelp AS | Arts & recreation | 2023 |
| Manuskript Forlag AS | Information & communication | 2020 |
| Manuzio AS | Information & communication | 2020 |
| Many Talents AS | Arts & recreation | 2026 |
| Manyar AS | Information & communication | 2015 |
| Manyone Norway AS | Information & communication | 2019 |
| Manzano Service Group AS | Wholesale & retail | 2021 |
| Manzoni AS | Wholesale & retail | 2015 |
| Maog AS | | 2025 |
| Maou AS | Wholesale & retail | 2025 |
| Maoui Invest AS | | 2020 |
| Map Arkitekter AS | Professional & scientific | 2008 |
| Map Holdco AS | Financial services | 2017 |
| Mapadam AS | | 2023 |
| Mapco AS | Professional & scientific | 2026 |
| Mape AS | | 2025 |
| Mapea AS | | 2019 |
| Mapea Nova AS | | 2025 |
| Mapilica AS | | 2023 |
| Maple AS | | 2019 |
| Maple Hill AS | | 2019 |
| Maple Tree Capital AS | Real estate | 2021 |
| Mapographics AS | Information & communication | 2014 |
| Mappeløs AS | Health & social care | 2018 |
| Mappen Holding AS | Real estate | 1998 |
| Maqhama Collection Nuf | Wholesale & retail | 2021 |
| Maqsood Eiendom AS | Real estate | 2019 |
| Maqsood Holding AS | Real estate | 2017 |
| Maqsood Invest AS | | 2022 |
| Mara Capital AS | | 2005 |
| Mara Invest AS | | 2022 |
| Marabu Scandinavia, Filial I Norge Nuf | Wholesale & retail | 1999 |
| Marad AS | Real estate | 2007 |
| Maradona Invest AS | | 2018 |
| Marais AS | | 2021 |
| Marajah AS | Hospitality | 2015 |
| Maralkunst AS | Wholesale & retail | 2020 |
| Marama Gaming AS | Arts & recreation | 2007 |
| Maranga AS | Wholesale & retail | 2016 |
| Marat Nuf | Information & communication | 2006 |
| Marathon Holding AS | Financial services | 2013 |
| Maraton Holding AS | Professional & scientific | 2019 |
| Maraton Sports Group AS | Arts & recreation | 2018 |
| Marbella Development AS | Real estate | 2019 |
| Marbella Eiendom AS | Real estate | 2000 |
| Marbella Invest AS | | 2020 |
| Marbella Property Investment AS | Real estate | 2012 |
| Marble Arch Holding AS | | 2025 |
| Marblecat Software AS | Information & communication | 2013 |
| Marbles Music Ans | Arts & recreation | 2021 |
| Marbs AS | Wholesale & retail | 2016 |
| Marby Eiendom AS | Real estate | 1985 |
| Marc Management AS | Professional & scientific | 2021 |
| Marc O Polo Norge AS | Professional & scientific | 1991 |
| Marcarum AS | | 2021 |
| Marcel Invest AS | | 2021 |
| Marceni AS | Real estate | 2003 |
| Marchand Eiendom Ans | Real estate | 1993 |
| Marchant Invest AS | Information & communication | 2006 |
| Marche AS | Professional & scientific | 2004 |
| Marchfirst Advisory AS | Professional & scientific | 2020 |
| Marchfirst Invest AS | Professional & scientific | 2020 |
| Marchfirst Management AS | Real estate | 2003 |
| Marchfirst Norway AS | Professional & scientific | 1999 |
| Marciano Holding AS | | 2023 |
| Marcini AS | Wholesale & retail | 2025 |
| Marco Boella | Professional & scientific | 2010 |
| Marco Offshore & Shipping AS | Real estate | 2005 |
| Marco Polo AS | Wholesale & retail | 1999 |
| Marco Polo Travel AS | Transport & logistics | 2003 |
| Marco Reklame AS | Professional & scientific | 2000 |
| MARCONTACT, Ansv. Selskap | | 1986 |
| Marcs Film AS | Arts & recreation | 2018 |
| Marcus Arnbekk AS | Arts & recreation | 2019 |
| Marcus Bergquist Holding AS | | 2024 |
| Marcus Thranes Vei 2 Eiendom AS | Real estate | 2013 |
| Marcus Thranes Vei 86 B AS | Real estate | 2025 |
| Marcus Thranesvei 58 Eiendom AS | Real estate | 2013 |
| Marcusinco AS | Financial services | 2005 |
| Marcussen Shipping AS | Transport & logistics | 2005 |
| Mardal Forsikring AS | Financial services | 2022 |
| Mardal Holding AS | Financial services | 2022 |
| Mardin Oslo AS | Hospitality | 2026 |
| Mardra Holding AS | | 2023 |
| Mare AS | Real estate | 2000 |
| Mare Bunadtilvirkere AS | Manufacturing | 2023 |