| Murmestercompaniet Løkken & Tollefsjord AS | Construction | 2005 |
| Murre Holding AS | | 2025 |
| Musikkprofil Booking Og Management AS | Professional & scientific | 2014 |
| Mustvedt AS | Transport & logistics | 1997 |
| MW Earth Holding AS | Wholesale & retail | 2005 |
| My En AS | Real estate | 2021 |
| My Revolution AS | Wholesale & retail | 2015 |
| Myhra Geir Aut Elinstallatør AS | Construction | 2013 |
| Myhra Holding AS | Financial services | 2024 |
| Mykle Consult AS | Professional & scientific | 2021 |
| Myra Bamble AS | Administrative & support | 2025 |
| Myren Parkering AS | Transport & logistics | 2013 |
| Myrstrand Holding AS | | 2025 |
| Myrvold AS | Real estate | 2015 |
| Myrvold Eiendom AS | Real estate | 2015 |
| Myrvold Holding AS | Construction | 2018 |
| MZ Invest AS | | 2024 |
| Matkammeret AS | Wholesale & retail | 1997 |
| Månevann AS | Information & communication | 2021 |
| Mælagata 33 AS | Real estate | 2016 |
| Mælagata 41 AS | Real estate | 2023 |
| Mælagata 8 AS | Real estate | 2026 |
| Mælagt 1 AS | Real estate | 2000 |
| Mælagt 73 AS | Real estate | 1998 |
| Møbelgalleriet Telemark AS | Wholesale & retail | 2004 |
| Møbelhuset Skien AS | Wholesale & retail | 2005 |
| Møbelinvest AS | Real estate | 2013 |
| Møllestua Da | Hospitality | 1994 |
| Mørjefjorden Nord Vann Og Avløp SA | Water & waste | 2008 |
| N-Øye AS | Health & social care | 2025 |
| N.A Holding AS | Real estate | 2018 |
| Naitsmania AS | Information & communication | 2013 |
| Nansetgata 8 AS | Real estate | 2017 |
| Naprapat Lindgaard AS | Health & social care | 2015 |
| Naranjos Holding AS | Real estate | 2012 |
| Naturpartner AS | Professional & scientific | 2012 |
| Naturskog AB | Professional & scientific | 2012 |
| Naturstein & Flis AS | Construction | 2018 |
| Naumar AS | Wholesale & retail | 2016 |
| Nautomation AS | Construction | 2020 |
| Navigalaxy AS | Other services | 2022 |
| Ndoka Investments AS | | 2025 |
| Nedenom AS | Hospitality | 2023 |
| Nedre Hjellegate 11 AS | Real estate | 2001 |
| Nedre Hjellegt 2 AS | Real estate | 1993 |
| Nedre Kongerød 39 AS | Real estate | 2026 |
| Nedre Kongerød 47 AS | Real estate | 2021 |
| Nemas AS | Administrative & support | 2025 |
| Nemesis Holding AS | Financial services | 2005 |
| Nenset Auto AS | Wholesale & retail | 2015 |
| Nenset Brukthandel Ans | Wholesale & retail | 1996 |
| Nenset Dekksenter AS | Wholesale & retail | 2019 |
| Nenset Glassverksted AS | Construction | 1999 |
| Nenseth Eiendom AS | Real estate | 1987 |
| Neocisma Holding AS | | 2025 |
| Neon Da | Wholesale & retail | 1997 |
| Nepa Norway AS | Professional & scientific | 2016 |
| Nesjar AS | Real estate | 1982 |
| Netica AS | Administrative & support | 2025 |
| Netpets AS | Wholesale & retail | 2016 |
| Nettpartner Norge AS | Information & communication | 2010 |
| Nevio AS | Information & communication | 2023 |
| Nevropsykolog Trine Lona AS | Health & social care | 2023 |
| New Agra Skien AS | Hospitality | 2017 |
| New House Ans | Construction | 2007 |
| New Normal Group AS | Information & communication | 2012 |
| New Normal Property AS | Real estate | 2022 |
| New Normal Venture AS | Information & communication | 2016 |
| Newco Cu 2026 AS | Wholesale & retail | 2025 |
| Newleaf AS | Arts & recreation | 2024 |
| Nextcall AS | Administrative & support | 2015 |
| Nicco Holding AS | Real estate | 2003 |
| Niels Juels Gate Utvikling AS | Real estate | 2023 |
| Nielve AS | Real estate | 2020 |
| Nilan AS | Professional & scientific | 2004 |
| Nils P Høyer & Son AS | Transport & logistics | 1926 |
| Nilsen Bygg AS | Real estate | 1988 |
| Nilsen Og Hartveit Tømrerfirma Da | Construction | 2003 |
| Nimtec AS | Professional & scientific | 2004 |
| Nina Kaffe & More AS | Hospitality | 2025 |
| Nina Therese Berg Holding AS | | 2026 |
| Nipe Invest AS | Construction | 2018 |
| Nisel Holding AS | | 2026 |
| Nite Investment AS | | 2022 |
| Niva Nails & Beauty AS | Other services | 2026 |
| NJE2015 AS | Real estate | 2015 |
| Nk-A AS | Real estate | 2013 |
| Nk-B AS | Real estate | 2013 |
| Nk-C AS | Real estate | 2013 |
| Nk-D AS | Real estate | 2013 |
| Nke Holding AS | Real estate | 2005 |
| No Bygg AS | Construction | 2015 |
| Noac Holding AS | Construction | 2014 |
| Nobotic AS | Information & communication | 2026 |
| Nocl AS | | 2026 |
| Noesis-Senter for Kreativitet Og Kommunikasjon Ans | Education | 2008 |
| Nomevegen AS | Real estate | 2007 |
| Nomevegen Holding AS | Real estate | 2021 |
| Nomvær Cæpital AS | Financial services | 2016 |
| Nong & Petters AS | | 2017 |