| MG Motrøen Holding AS | Real estate | 2018 |
| Midteng Østre AS | Financial services | 2012 |
| Midtvangen AS | Real estate | 2007 |
| Mila Bil AS | Wholesale & retail | 1987 |
| Milano Tynset AS | Hospitality | 2009 |
| Milky Way Samdrift Da | Agriculture & fishing | 2009 |
| Mink Holding AS | Construction | 2020 |
| MK Eiendom Tynset AS | Real estate | 2024 |
| MK Elektro AS | Construction | 2024 |
| MK Holding Tynset AS | Construction | 2024 |
| Mm&T Eiendom AS | Real estate | 2023 |
| Moan Aaen Maskinlag Da | Administrative & support | 2022 |
| Mobilgrus AS | Mining & quarrying | 2011 |
| Moens Eiendomsselskap AS | Real estate | 2008 |
| Moldstad Mur AS | Construction | 2024 |
| Moskusen AS | Real estate | 2014 |
| Mpe Maskin AS | Wholesale & retail | 2021 |
| MPK Eiendom AS | Real estate | 2023 |
| Mudo Gym Tynset AS | Arts & recreation | 2016 |
| Munken Holding AS | Financial services | 2005 |
| Myhre Eiendom AS | Real estate | 2002 |
| Mælen Maskin & Transport AS | Transport & logistics | 1975 |
| Na Eiendom AS | Real estate | 2021 |
| Naturfokus AS | Professional & scientific | 2025 |
| Naturlig Helse AS | Wholesale & retail | 2025 |
| Ndi Eiendom AS | Real estate | 2022 |
| Nednor Ict | Information & communication | 2009 |
| Nedre Glomsjø AS | Financial services | 2012 |
| Neklia Veilag SA | Real estate | 1973 |
| Nemo Brønnboring Og Maskin AS | Construction | 2007 |
| Nesseth Eiendom Og Holding AS | Mining & quarrying | 1988 |
| Neste Holding AS | | 2022 |
| Norax AS | Real estate | 2017 |
| Norax Tynset AS | Manufacturing | 2002 |
| Nord Østerdal Kraftlag Andelsverk AS | Energy | 1999 |
| Nord-Østerdal Bio AS | Agriculture & fishing | 2024 |
| Nord-Østerdal Fiber AS | Construction | 2019 |
| Nord-Østerdal Kraftlag SA | Energy | 1944 |
| Nord-Østerdal Utmarkstjenester AS | Professional & scientific | 2012 |
| Nordavind Energy Sites AS | Real estate | 2015 |
| Nordic Tracker AS | Information & communication | 2019 |
| Nordstad Holding AS | Real estate | 2010 |
| Nordøstkonsult AS | Professional & scientific | 1974 |
| Norsk Spekematfestival AS | Arts & recreation | 2016 |
| Norsport AS | Wholesale & retail | 2013 |
| Nye Aumlia Beite- Og Sankelag SA | Agriculture & fishing | 1975 |
| Nye Hus Tynset AS | Construction | 2026 |
| Nygard Johansen Holding AS | | 2026 |
| Nygårdshaug Holding AS | | 2019 |
| Nytrøa Grunneierlag SA | Real estate | 1971 |
| Nytrøen Eiendom AS | Real estate | 2015 |
| Nytrøen Holding AS | Real estate | 2012 |
| Nyutstumoen Holding Og Eiendom AS | Real estate | 2010 |
| Nøk Biovarme AS | Energy | 1999 |
| Nøk Eiendom AS | Real estate | 2002 |
| Nøk Fornybar AS | Energy | 2006 |
| Nøk Tomtegata 8 AS | Real estate | 2019 |
| Nøk Vind AS | Energy | 2025 |
| Nøk Vind Holding AS | Energy | 2024 |
| Oar AS | Real estate | 2008 |
| Odd Amund Dølmo AS | | 2000 |
| Odd Rune Gjeitanger AS | Wholesale & retail | 2018 |
| Opsand Eiendom AS | Real estate | 1995 |
| Optiscan Nuf | Information & communication | 2007 |
| Orkideekspressen Østerdal Reisebyrå AS | Administrative & support | 1984 |
| Outdoormotor Tynset AS | Wholesale & retail | 2001 |
| Parkveien 1 Eiendom AS | Real estate | 2015 |
| Parkveien 6-8 AS | Real estate | 2007 |
| Parkveien Eiendom AS | Real estate | 1998 |
| Per Henning Fiskvik Transport AS | Transport & logistics | 2008 |
| Phillips Eiendom AS | Real estate | 2008 |
| Phillips Eiendom Hamar AS | Real estate | 1973 |
| Phillips Eiendom Koppang AS | Real estate | 2013 |
| Phillips Eiendom Rena AS | Real estate | 2015 |
| Phillips Eiendom Stange AS | Real estate | 1974 |
| Phillips Eiendom Trondhjem AS | Construction | 2020 |
| Phillips Eiendom Tynset AS | Real estate | 2025 |
| PKL Holding AS | | 2023 |
| Preambulum Orgelkonsult AS | Arts & recreation | 2017 |
| Printn AS | Professional & scientific | 2024 |
| Prohouses Norge AS | Construction | 2022 |
| PTH AS | Real estate | 2012 |
| PTH Eiendom AS | Real estate | 2021 |
| Raedergaard Holding AS | | 2019 |
| Raedergaard Property AS | Real estate | 2026 |
| Rausjødalen Setermeieri AS | Arts & recreation | 2024 |
| Revisorkonsult AS | Professional & scientific | 1983 |
| Risegga Holding AS | Wholesale & retail | 2020 |
| RK Rådgivning AS | Professional & scientific | 2011 |
| Rkrr Eiendom Ans | Real estate | 1989 |
| Rous Holding AS | | 2026 |
| RPG AS | Wholesale & retail | 2017 |
| Rumikk Holding AS | | 2025 |
| Rundkjøringa Eiendom AS | Real estate | 2015 |
| Rå! Kompetanse AS | Professional & scientific | 2021 |
| Rødalshøa Invest AS | | 2026 |
| Rønningen Utvikling AS | Health & social care | 2025 |
| Rørlegger'N Bauer AS | Construction | 2021 |
| Røros Fritidsbygg AS | Construction | 2017 |
| Rørservice Tynset AS | Construction | 2007 |