| Massiv AS | Professional & scientific | 2025 |
| Massiv Lust AS | Manufacturing | 2011 |
| Massive Scandinavia AS | Wholesale & retail | 1995 |
| Massivo AS | Information & communication | 2026 |
| Mast Invest Da | | 2000 |
| Mast- Och Tornunderhåll Sverige Aktiebolag Nuf | Construction | 2017 |
| Mastabert Da | Manufacturing | 2009 |
| Mastda AS | | 2025 |
| Mastemyr Bygg AS | Real estate | 1986 |
| Mastemyr Infrastruktur AS | Real estate | 2019 |
| Master International Food AS | Wholesale & retail | 2022 |
| Master Management Norge AS | Education | 2002 |
| Master Renhold & Vaktmester Service AS | Administrative & support | 2018 |
| Masterbad AS | Construction | 2021 |
| Mastercard Europe | Professional & scientific | 2015 |
| Mastercard Payment Services Infrastructure (Norway) AS | Information & communication | 2019 |
| Mastercard Payment Services Norway AS | Information & communication | 2019 |
| Masterchannel AS | Information & communication | 2020 |
| Masterklinikken Norge AS | Health & social care | 2014 |
| Mastermind Holding AS | Health & social care | 2017 |
| Mastermovement AS | Transport & logistics | 2024 |
| Masterpiece Tattoo AS | Real estate | 2022 |
| Mastersons Holding AS | | 2026 |
| Mastervantage AS | Information & communication | 2025 |
| Masti Food AS | Hospitality | 2025 |
| Mastiago AS | Real estate | 2009 |
| Mastiff AS | Information & communication | 1992 |
| Mastiff Entertainment AS | Information & communication | 1994 |
| Mastra AS | | 2022 |
| Masvie Holding AS | | 2022 |
| Mat & Drikke AS | Hospitality | 2025 |
| Mat & Mer Bjølsen AS | Hospitality | 2013 |
| Mat for Moms AS | Hospitality | 2021 |
| Mat Fra Banat AS | Hospitality | 2026 |
| Mat Fra Marcus AS | Hospitality | 2019 |
| Mat Og Kos AS | Hospitality | 2019 |
| Mat Og Kulturkompetanse AS | Hospitality | 2025 |
| Mat Og Musikk AS | Hospitality | 2019 |
| Mat Og Vin Gruppen AS | Hospitality | 2013 |
| Mat Overalt AS | | 2025 |
| Mat Produkter AS | Wholesale & retail | 2022 |
| Mat Til En Hver Smak AS | Hospitality | 2026 |
| Matabe AS | | 2023 |
| Matador Capital AS | | 2021 |
| Mataji AS | | 2007 |
| Matak Holding AS | Financial services | 2013 |
| Matarazzo AS | Professional & scientific | 2009 |
| Matark AS | Professional & scientific | 2021 |
| Matas Norge AS | Wholesale & retail | 2023 |
| Matata Creatives AS | Arts & recreation | 2021 |
| Matato AS | Information & communication | 2025 |
| Matbaren Fredrikstad AS | Hospitality | 2024 |
| Matbyrået AS | Hospitality | 2015 |
| Matca Advisory AS | Professional & scientific | 2024 |
| Match Eiendom AS | Real estate | 2012 |
| Match Kompetanse AS | Administrative & support | 2018 |
| Matcha Holding AS | | 2025 |
| Matcha Sushi Bar AS | Hospitality | 2016 |
| Matchbox Design STUDI0 Da | Professional & scientific | 2001 |
| Matchless AS | Real estate | 2017 |
| Matchmaker AS | Professional & scientific | 2007 |
| Matchwork Ans | Administrative & support | 1992 |
| Matconsult AS | Wholesale & retail | 2024 |
| Matduo Ans | Hospitality | 2004 |
| Mate Consulting AS | Information & communication | 2026 |
| Mate Invest AS | Financial services | 2013 |
| Matehe Holding AS | | 2022 |
| Matenso AS | Health & social care | 2021 |
| Mater AS | Information & communication | 1964 |
| Matera AS | Professional & scientific | 2024 |
| Matera Eiendom AS | Real estate | 2024 |
| Matera PM AS | Professional & scientific | 2026 |
| Materia AS | Information & communication | 2020 |
| Material Biomimetic AS | Real estate | 2012 |
| Material Girl AS | | 2017 |
| Materialhuset AS | Administrative & support | 2006 |
| Materialize Consulting AS | Information & communication | 2013 |
| Materna Norway AS | Information & communication | 2023 |
| Matexpressen AS | Hospitality | 1991 |
| Matglad AS | Wholesale & retail | 2005 |
| Matglede I Oslo AS | Hospitality | 2025 |
| Matgleden Ans | Wholesale & retail | 1992 |
| Matha AS | | 2016 |
| Mathallen AS | Real estate | 2008 |
| Mather AS | Professional & scientific | 2019 |
| Matheson Risk Management AS | Financial services | 2008 |
| Mathias Aas Stoltenberg AS | Arts & recreation | 2025 |
| Mathias Beck AS | | 2026 |
| Mathias G Helseth Holding AS | | 2021 |
| Mathias Invest AS | | 2024 |
| Mathias Jansen Arkitektkontor AS | Professional & scientific | 2026 |
| Mathias Løvlie Holding AS | | 2020 |
| Mathias Marstrander AS | Arts & recreation | 2023 |
| Mathiesen Holding AS | Information & communication | 2022 |
| Mathilda Invest AS | Wholesale & retail | 2005 |
| Mathilde Maude AS | | 2026 |
| Mathilde SPZ AS | Arts & recreation | 2024 |
| Mathinco AS | Financial services | 2001 |
| Mathis Borthen AS | Health & social care | 2021 |
| Mathisen Automasjon AS | Construction | 2024 |