| Martinc Invest AS | | 2026 |
| Martine Barneklær AS | Wholesale & retail | 2017 |
| Martine Designs AS | Professional & scientific | 2024 |
| Martine Eid AS | Arts & recreation | 2016 |
| Martine Ek Rønning AS | Wholesale & retail | 2024 |
| Martine Hattestad Kveli AS | Arts & recreation | 2026 |
| Martine Johansen AS | Arts & recreation | 2021 |
| Martine M AS | | 2019 |
| Martinez AS | Professional & scientific | 2025 |
| Martingale Invest Nuf | Information & communication | 2006 |
| Martini Invest AS | Professional & scientific | 2012 |
| Martinmann AS | Arts & recreation | 2023 |
| Martino Handel AS | Wholesale & retail | 2001 |
| Martins Auto AS | Wholesale & retail | 2020 |
| Martinsen Bad & Bolig AS | Construction | 2016 |
| Martinsen Group AS | Wholesale & retail | 2015 |
| Martinsen Media AS | Professional & scientific | 2022 |
| Martinus Invest AS | Real estate | 2006 |
| Martinussen Holding AS | Real estate | 2005 |
| Martinuzzi AS | Professional & scientific | 2017 |
| Martor Invest AS | Professional & scientific | 2015 |
| Maru AS | Wholesale & retail | 2021 |
| Marulke AS | Real estate | 2014 |
| Marusia Invest AS | Professional & scientific | 2022 |
| Marv Invest AS | | 2024 |
| Marva Capital Limited | Professional & scientific | 2023 |
| Marve AS | | 2020 |
| Marvel Holding AS | Real estate | 2008 |
| Marvid AS | Professional & scientific | 2022 |
| Marvil AS | Financial services | 2016 |
| Marvist Capital AS | Wholesale & retail | 2020 |
| Marxpist Invest AS | Financial services | 2000 |
| Mary Indiana AS | Wholesale & retail | 2015 |
| Mary Jane Gaver Og Klær Da | Wholesale & retail | 1988 |
| Maryam Invest AS | Real estate | 2020 |
| Maryetta AS | Financial services | 1948 |
| Marylebone Holding AS | Financial services | 2017 |
| Marylebone Invest AS | Financial services | 2015 |
| Marysol Sand AS | Hospitality | 2021 |
| Mas & Co AS | Real estate | 2015 |
| Mas Entreprenør AS | Construction | 2019 |
| Mas Hjula Holding AS | | 2021 |
| Mas Holdings AS | | 2026 |
| Mas Taxi AS | Transport & logistics | 2024 |
| Masa Investor AS | | 2026 |
| Masala AS | Hospitality | 2019 |
| Masala Politics AS | Hospitality | 2024 |
| Masalabox AS | Hospitality | 2019 |
| Masalamagic AS | Wholesale & retail | 2008 |
| Masan AS | Real estate | 2017 |
| Masarati AS | Arts & recreation | 2021 |
| Masb AS | | 2020 |
| Masc Invest AS | | 2025 |
| Maschmanns AS | Wholesale & retail | 2011 |
| Mase Home AS | Professional & scientific | 2023 |
| Masema AS | Professional & scientific | 2012 |
| Maseng AS | Information & communication | 2015 |
| Maseo AS | | 2021 |
| Maser Management Services AS | Professional & scientific | 1997 |
| Mash Agency AS | Professional & scientific | 2026 |
| Mash Brands Norway AS | Wholesale & retail | 2022 |
| Mash Eiendom AS | Real estate | 2018 |
| Mash Food & Beverage AS | Hospitality | 2022 |
| Mash Holding AS | | 2023 |
| Mash Markets AS | Wholesale & retail | 2023 |
| Mash Studios Gamlebyen AS | Education | 2020 |
| Mash Studios Norway AS | Real estate | 2019 |
| Mash Training AS | | 2023 |
| Mash Universe AS | Education | 2021 |
| Mashed Potato Club AS | Hospitality | 2017 |
| Mashti Community AS | Education | 2024 |
| Masina AS | Information & communication | 2025 |
| Masive Holding AS | Real estate | 2013 |
| Mask Utvikling AS | | 2018 |
| Maskast AS | | 2024 |
| Maskin AS Sterling | Administrative & support | 1940 |
| Maskinbygg AS | Construction | 2009 |
| Maskinen AS | Professional & scientific | 2010 |
| Maskinentreprenør Helling AS | Construction | 2023 |
| Maskineriet Forsikring AS | Administrative & support | 2024 |
| Maskinexport AS | Wholesale & retail | 2016 |
| Maskinforum AS | Administrative & support | 1983 |
| Maskinlink AS | Wholesale & retail | 2019 |
| Maskinspecialisten AS | Manufacturing | 1963 |
| Maskinveien 1 AS | Real estate | 2004 |
| Maskot AS | Arts & recreation | 2022 |
| Masmasmas AS | Professional & scientific | 2023 |
| Masom Holding AS | | 2021 |
| Masonry AS | Information & communication | 2020 |
| Masorm AS | Real estate | 2006 |
| Masovi AS | Information & communication | 2022 |
| Masp Holding AS | Financial services | 2015 |
| Maspa Holding AS | | 2024 |
| Maspc Limited | Wholesale & retail | 2020 |
| Mass Group AS | | 2021 |
| Mass Production Da | Professional & scientific | 2016 |
| Massa AS | Professional & scientific | 2018 |
| Masse Maling & Bygg AS | Construction | 2024 |
| Masseh Mat AS | Wholesale & retail | 2005 |
| Massimo AS | Real estate | 2008 |