| Morild Boats AS | Manufacturing | 2020 |
| Mormors Kjeller AS | Real estate | 2025 |
| MR. Singh Bilpleie Og Vedlikehold AS | Other services | 2012 |
| MRS Volcano AS | Hospitality | 2019 |
| MS Dr.Skogsholm AS | Manufacturing | 2021 |
| MS Media Group AS | Information & communication | 2018 |
| MS. Bubble Tea AS | Hospitality | 2012 |
| Msamuelsen Holding AS | | 2024 |
| Mship Norway AS | Professional & scientific | 2023 |
| MSM Entertainment AS | Administrative & support | 2020 |
| MSV Holding AS | Real estate | 2017 |
| MT Eiendomsinvest AS | Real estate | 2013 |
| MT Pepita AS | Wholesale & retail | 1992 |
| MTL Holding AS | | 2026 |
| Mttl Eiendom AS | | 2026 |
| Muj AS | | 2026 |
| Mulk AS | Information & communication | 2023 |
| Multi Agro AS | Agriculture & fishing | 2015 |
| Multi Group AS | Financial services | 2013 |
| Multi Investment AS | Financial services | 2013 |
| Multibo Entreprenør AS | Professional & scientific | 2024 |
| Multiserve Solutions AS | Administrative & support | 2024 |
| Mumu AS | Administrative & support | 2024 |
| Munkebakken 1 AS | Households | 1954 |
| Munkegata 7B AS | Real estate | 2022 |
| Munkegaten 3 AS | Real estate | 1987 |
| Munkerekkveien 4 AS | Real estate | 2021 |
| Murmester Morten P Håkonsen AS | Construction | 2014 |
| Murmester Ole a. Broen AS | Construction | 1988 |
| Musikk Og Eiendom Da | Real estate | 2010 |
| Muslingen Holding AS | Financial services | 2008 |
| My Asiamat Og Grønnsaker AS | Wholesale & retail | 2006 |
| My Space AS | Real estate | 2024 |
| Myhrland AS | Professional & scientific | 2005 |
| Mysi Tekstil AS | Professional & scientific | 2025 |
| Mythos Eiendom AS | Information & communication | 2005 |
| Mythos Holding AS | Information & communication | 2005 |
| Mytteriet AS | Hospitality | 2010 |
| Måkeveien 1 a Tønsberg AS | Real estate | 2005 |
| Måkeveien 1 B AS | Real estate | 2008 |
| Måkeveien 2 a AS | Real estate | 2004 |
| Måltid SA | Transport & logistics | 2026 |
| Møbelringen Tønsberg AS | Wholesale & retail | 2018 |
| Møllegaten 1 Og 3 AS | Real estate | 1951 |
| Møllegaten 8 AS | Real estate | 2014 |
| Møller Bil Vestfold AS | Other services | 1988 |
| Mølleveien 31 AS | Transport & logistics | 2013 |
| Mørck-Olaussen Holding AS | Financial services | 2017 |
| N.K Bygg AS | Construction | 2017 |
| Nach AS | Hospitality | 2021 |
| Nakrihavi AS | Real estate | 2014 |
| Namnor AS | Wholesale & retail | 2016 |
| Namsos Jernvareforretning AS | Health & social care | 1933 |
| Nanak AS | Health & social care | 2025 |
| Nansen & Nansen AS | Construction | 2009 |
| Naprapat Nakling AS | Health & social care | 2017 |
| Narko Norge AS | Wholesale & retail | 1997 |
| Narverød Byggservice AS | Construction | 2025 |
| Narverødveien 40 a AS | Real estate | 2014 |
| Narverødveien 40 AS | Real estate | 1970 |
| Narverødveien 47 AS | Real estate | 2024 |
| Narverødvn. 40 Holding AS | Real estate | 2010 |
| Nasjonalt Kompetanseregister AS | Professional & scientific | 2009 |
| Naturflid AS | Wholesale & retail | 2026 |
| Naverfjorden Vann Og Avløp AS | Water & waste | 2017 |
| NB Masterhus AS | Administrative & support | 2022 |
| Nedergaard/Transporter Ltd Nuf | Transport & logistics | 2019 |
| Nedre Langgate 20 AS | Real estate | 2008 |
| Nedre Langgate 28 AS | Real estate | 2005 |
| Nedre Langgate 28B AS | Real estate | 2020 |
| Nedregt 43 Ans | Real estate | 1997 |
| Neighbourhood AS | Professional & scientific | 2014 |
| Nell Holding AS | | 2026 |
| Nell Renhold AS | Administrative & support | 1986 |
| Nemus Tønsberg Helseklinikk AS | Health & social care | 2014 |
| Neoz Tønsberg AS | Wholesale & retail | 2019 |
| Nesten Holding AS | | 2025 |
| Netsolution Vestfold Og Telemark AS | Wholesale & retail | 2004 |
| Networco AS | Information & communication | 2025 |
| Newarc AS | Wholesale & retail | 2006 |
| Nexus Frisør AS | Other services | 2017 |
| Nexus Frisør Eiendom AS | Real estate | 2011 |
| Ni-Con AS | Professional & scientific | 2009 |
| Niba Holding AS | Professional & scientific | 2019 |
| Nicolai Rud Invest AS | Wholesale & retail | 2016 |
| Nihiltime AS | Real estate | 2010 |
| Nikama Invest AS | Real estate | 2019 |
| Nilto AS | Information & communication | 2017 |
| NL 28A-3 AS | Real estate | 2025 |
| Noa Lrrs Hooks AS | Wholesale & retail | 2020 |
| Noca Invest AS | Real estate | 2000 |
| Norblock A/S | Mining & quarrying | 1987 |
| Nordahl & Nicolaidis Eiendom AS | Real estate | 2017 |
| Nordahl & Nicolaidis Holding AS | Health & social care | 2017 |
| Nordal Byggservice AS | Construction | 2016 |
| Nordby Technology AS | Information & communication | 2016 |
| Nordbyen Garasjelag SA | Real estate | 1984 |
| Norden - Water AS | Wholesale & retail | 2020 |
| Norderhaug Invest AS | Real estate | 2025 |
| Nordic App Lab AS | Information & communication | 2026 |