| Meier AS | Construction | 2024 |
| Mennesker Og Natur AS | Health & social care | 2021 |
| Metro Rør AS | Construction | 2018 |
| Micro AS | Wholesale & retail | 1991 |
| Mileve AS | Administrative & support | 2018 |
| Miljøsparing AS | Wholesale & retail | 2015 |
| Min Helsebank Norge AS | Professional & scientific | 2011 |
| Miniskog AS | Administrative & support | 2026 |
| MK Consult AS | Health & social care | 2020 |
| Moa Promotering AS | Professional & scientific | 2017 |
| Modify AS | Professional & scientific | 2023 |
| Mogu AS | | 2007 |
| Moodizt AS | Wholesale & retail | 2017 |
| Morilden AS | Real estate | 1999 |
| Morland AS | Professional & scientific | 2014 |
| Morten Eriksrud AS | Transport & logistics | 2008 |
| Motorsport AS | Professional & scientific | 2016 |
| MPV Vognskjulet AS | Wholesale & retail | 2010 |
| Multi Pro Eiendom AS | Real estate | 2004 |
| Munken Drift AS | Real estate | 2006 |
| Mur & Flisarbeider AS | Construction | 2020 |
| MVP AS | Manufacturing | 1987 |
| Mysun Øst AS | Other services | 2012 |
| Møbelstoppen AS | Manufacturing | 2019 |
| Mølla Eiendom AS | Real estate | 1995 |
| Mørkassel Vann Og Avløp SA | Water & waste | 2018 |
| N&M Holding AS | | 2026 |
| N&M Vaktmesterservice AS | Administrative & support | 2013 |
| Nans AS | Information & communication | 2026 |
| Narjord AS | Financial services | 2017 |
| NCT Motorsport Da | Wholesale & retail | 2020 |
| Nefab Packaging Norway AS | Manufacturing | 1990 |
| Nemaa Invest AS | Real estate | 2018 |
| Nemi Bygg Og Takst AS | | 2020 |
| Nep Switchboards AS | Manufacturing | 2023 |
| Nepse AS | Financial services | 2015 |
| NH Eiendomsutvikling AS | Real estate | 2021 |
| Nicolai Nansen AS | Wholesale & retail | 2018 |
| Nilsen Maskin & Bygg AS | Construction | 2026 |
| Nora Supaprang Rakkenes Språk Og Kultur Tjeneste AS | Professional & scientific | 2022 |
| Norcana AS | Real estate | 2023 |
| Nordby Terrasse Eiendom AS | Real estate | 2015 |
| Nordic AI Motion Pictures AS | Information & communication | 2026 |
| Nordicepod AS | Manufacturing | 2022 |
| Nordisk Kapital AS | Wholesale & retail | 2023 |
| Nordkon AS | Information & communication | 2014 |
| Nordre Jarlsberg Badstue AS | Administrative & support | 2024 |
| Nordre Jarlsberg Elektro AS | Construction | 2017 |
| Nordre Jarlsberg Rør AS | Construction | 2025 |
| Nordwork AS | Administrative & support | 2025 |
| Nordåsen Va-Anlegg SA | Water & waste | 2017 |
| Norisp AS | Information & communication | 2007 |
| Norsk Gummi AS | Manufacturing | 1987 |
| Norsk Kranpartner AS | Professional & scientific | 2000 |
| Norsk Vannskjæring AS | Manufacturing | 2002 |
| Norske Kaninprodukter AS | Manufacturing | 2016 |
| Nva AS | Transport & logistics | 2014 |
| NorSafe A/S | Wholesale & retail | 1988 |
| Nøkkel-Ferdig Drift AS | Real estate | 2024 |
| Nøsted Brygge Badstue AS | Arts & recreation | 2025 |
| O.R.M AS | Financial services | 2005 |
| O.S.Espegard Holding AS | Real estate | 2020 |
| Obv Holding AS | | 2013 |
| Odloinvest AS | Real estate | 2025 |
| Oee Maskin AS | Administrative & support | 2014 |
| Ogri AS | Professional & scientific | 2005 |
| Ogri Consulting AS | Professional & scientific | 2017 |
| Ohmeohmy Nuf | Wholesale & retail | 2022 |
| Ojl Invest AS | Real estate | 2005 |
| Ola Vold Invest AS | | 2018 |
| Olafsen AS | Professional & scientific | 2024 |
| Olaussen Consult AS | Education | 2013 |
| Oljefix AS | Wholesale & retail | 2021 |
| Olsens Enke Sande AS | Wholesale & retail | 2018 |
| Opplevelsen Da | Health & social care | 2003 |
| Oreberg Utvikling AS | Real estate | 2017 |
| Oretun AS | Professional & scientific | 2005 |
| Orhusveien 1 AS | Real estate | 2018 |
| Orhusveien 10 AS | Real estate | 2018 |
| Orhusveien 2 AS | Real estate | 2018 |
| Orion Prosjekter AS | Real estate | 1976 |
| Orvekst Invest AS | Professional & scientific | 2005 |
| Osco Oslocomfort AS | Construction | 2026 |
| Outboardservice Sande AS | Manufacturing | 2014 |
| Oves Byggteknikk AS | Construction | 2013 |
| P&L Eiendomsutvikling AS | Real estate | 2024 |
| Paalerud & Thorsen Da | Other services | 2024 |
| Pabeha Invest AS | | 2019 |
| Paletten Restaurant AS | Hospitality | 2015 |
| Palma Auto AS | Wholesale & retail | 2024 |
| Palma Holding AS | Real estate | 2021 |
| Pangora AS | Information & communication | 2020 |
| Panman AS | Financial services | 2013 |
| Partex Marking Systems Norway AS | Manufacturing | 2001 |
| Paulgaard AS | Financial services | 2013 |
| Pearl Harbo AS | Professional & scientific | 2012 |
| Pedersen Bilsalg AS | Wholesale & retail | 2005 |
| Per Gynt Lodge AS | Real estate | 2024 |
| Per Reese Maskin AS | Administrative & support | 2012 |
| Peri Norge AS | Wholesale & retail | 1990 |