| Magne Abrahamsen Holding AS | Wholesale & retail | 2017 |
| Malerfirmaet Tore Ask & Sønn AS | Construction | 1995 |
| Marella AS | Real estate | 1993 |
| Marella Eiendom AS | Real estate | 2003 |
| Mariero Equine Products AS | Wholesale & retail | 2023 |
| Maritim Start AS | Wholesale & retail | 2016 |
| Maskin Og Truckservice AS | Manufacturing | 2019 |
| Matbørsen AS | Manufacturing | 1994 |
| Matprodusenten AS | Manufacturing | 2007 |
| Medic Fot AS | Health & social care | 2021 |
| Medic Fot Stokke AS | Health & social care | 2020 |
| Meiser Norway AS | Manufacturing | 1988 |
| Melsomvikveien 6A AS | Real estate | 2013 |
| Melsomvikveien AS | Real estate | 2023 |
| Mementoit AS | Information & communication | 2021 |
| Mester HJM AS | Construction | 2024 |
| Mesterverk Innredninger AS | Construction | 2020 |
| Metso Norway AS | Wholesale & retail | 1898 |
| Mikkelsen & Mikkelsen AS | Construction | 2005 |
| Mikkelsen Maskin & Eiendom AS | Real estate | 2008 |
| Milav AS | Transport & logistics | 2024 |
| Milena AS | Other services | 2016 |
| Milena Eiendom AS | Real estate | 2021 |
| Miljøpall AS | Wholesale & retail | 2022 |
| Millemåne AS | Wholesale & retail | 2007 |
| Mindrum Transport AS | Transport & logistics | 1991 |
| Ministing AS | Wholesale & retail | 2017 |
| Mitt Kjøleskap Da | Information & communication | 2026 |
| Mjølner Group AS | Education | 2025 |
| MKB Holding AS | Financial services | 2007 |
| Mogtek AS | Wholesale & retail | 1992 |
| Moien AS | | 2021 |
| Moka Eiendom AS | Real estate | 2013 |
| Molo Design AS | Professional & scientific | 2016 |
| Momork Holding AS | Real estate | 2017 |
| Mona Hansen Fysioterapi AS | Health & social care | 2024 |
| Mona Lise Holding AS | Administrative & support | 2005 |
| Montør Bjønness AS | Construction | 2012 |
| Montør Bjønness Gårdssikring AS | Construction | 2026 |
| Mor Aase Holding AS | | 2007 |
| Moreneveien 2 AS | Real estate | 2024 |
| Motor Service AS | Wholesale & retail | 2016 |
| MTW Holding AS | Real estate | 2007 |
| Multi-Metall AS | Manufacturing | 2020 |
| Munarheim Holding AS | Health & social care | 2022 |
| Muscle Therapy AS | Wholesale & retail | 2024 |
| Muvy AS | Information & communication | 2026 |
| Myrvang AS | Real estate | 1997 |
| Nabone Trenshop Da | Wholesale & retail | 1988 |
| Naturmagi AS | Other services | 2025 |
| Neotemp Installasjon AS | Construction | 2025 |
| New Momentum AS | | 2023 |
| Niche Norway AS | Wholesale & retail | 2009 |
| Nika Norge AS | Wholesale & retail | 2017 |
| Nima AS | Manufacturing | 1994 |
| Nita AS | Wholesale & retail | 2017 |
| Nor Slep AS | Manufacturing | 1983 |
| Nordic Peak AS | | 2025 |
| Nordicframing AS | Professional & scientific | 2018 |
| Nordpett Group AS | Construction | 2024 |
| Nordpett Innglassing AS | Construction | 2023 |
| Nordpett Solar AS | Construction | 2021 |
| Norlux AS | Wholesale & retail | 1991 |
| Norse Marketing AS | Professional & scientific | 2025 |
| Norsk Bil Og Maskininnkjøp AS | Wholesale & retail | 2024 |
| Norsk Ombruk AS | Wholesale & retail | 2014 |
| Norsk Stavlaft AS | Real estate | 2015 |
| Norwegian Sports Group AS | Wholesale & retail | 1974 |
| Novotak AS | Construction | 2024 |
| Nowoshop AS | Wholesale & retail | 2007 |
| NP Bygg Og Anlegg AS | Construction | 2023 |
| NP Solution AS | Information & communication | 2024 |
| NRG Bygg AS | Real estate | 2020 |
| Nye Vilja AS | | 2026 |
| Nye Vilja Holding AS | | 2026 |
| Nygaards Allé 3 AS | Real estate | 2008 |
| Nøste Venture AS | | 2026 |
| Nøtterøy Asfalt AS | Construction | 1987 |
| O-S Invest AS | Real estate | 2024 |
| Okso Eiendom AS | Real estate | 2022 |
| Ole Bekken Holding AS | Real estate | 2013 |
| Ole R.J.Holding AS | | 2023 |
| Olsrød Transport AS | Transport & logistics | 2021 |
| Omtrekk Verkstedet AS | Other services | 2021 |
| Onsrud Eiendom AS | Real estate | 2023 |
| Onsrud Taksering AS | Professional & scientific | 2021 |
| Oppmuntring AS | Wholesale & retail | 2016 |
| Opus Production AS | Manufacturing | 1998 |
| Ormestad Invest AS | Wholesale & retail | 2020 |
| Oseberg Engineering AS | Professional & scientific | 2002 |
| Osmundsen Holding AS | Manufacturing | 2005 |
| Osp Invest AS | Financial services | 2015 |
| Ost-Online AS | Wholesale & retail | 2024 |
| Over Stokk Og Stein Transport Ans | Transport & logistics | 2005 |
| Pajo Invest AS | Real estate | 2021 |
| Pakke-Express AS | Transport & logistics | 2024 |
| Pastell AS | Construction | 2012 |
| Paulsen Buss AS | Transport & logistics | 2001 |
| Payandeh Dental AS | Health & social care | 2017 |
| PB Byggservice AS | Construction | 2019 |