| Røsteggen Invest AS | Real estate | 2004 |
| Røstvanglia Eiendom AS | Financial services | 2008 |
| S.Steen Invest AS | | 2024 |
| Salong Vi-Ka-El | Other services | 1983 |
| Samejakki Da | Wholesale & retail | 2016 |
| Savalen Aktiv AS | Arts & recreation | 2022 |
| Savalen Bygde & Hytteservice Da | Administrative & support | 2003 |
| Savalen Drift AS | Hospitality | 2003 |
| Savalen Fritidsboliger AS | Real estate | 2006 |
| Savalen Skiarena AS | Arts & recreation | 1990 |
| SE & Lær Ans | Administrative & support | 1997 |
| Sentrum Eiendom Tynset AS | Real estate | 2007 |
| Setervegene I Magnildalen SA | Real estate | 2018 |
| Sjalabais AS | Transport & logistics | 2018 |
| Sjoen Invest AS | | 2025 |
| SK Bygg Holding AS | | 2025 |
| Sk-Bygg AS | Construction | 1989 |
| Skaugum AS | | 2025 |
| Skei Utvikling AS | Real estate | 2001 |
| Ski in Fageråsen AS | Real estate | 2024 |
| Ski in Skeikampen AS | Real estate | 2021 |
| Snart Lisbeth Sitt AS | Real estate | 2024 |
| Solbulåven AS | Wholesale & retail | 1997 |
| Solegga AS | Professional & scientific | 2016 |
| Solmo Invest AS | | 2025 |
| Spenning Holding AS | Construction | 2022 |
| Spergula AS | Education | 2020 |
| SPT Holding AS | Financial services | 2005 |
| SST Mote AS | Wholesale & retail | 2011 |
| Steien Auto Senter AS | Wholesale & retail | 2003 |
| Stemo Eiendom AS | Real estate | 1997 |
| Stemo Invest AS | Real estate | 1987 |
| Storeggen Gård AS | Manufacturing | 2021 |
| Storfossen AS | Construction | 2021 |
| Strandvik Holding AS | Financial services | 2018 |
| Strypet Bygg AS | Construction | 2018 |
| Strømmen Eiendom AS | Real estate | 2003 |
| Strømseng & Sagvang Drift Ans | Manufacturing | 2024 |
| Støholen Eiendom AS | Real estate | 1975 |
| Sundlings Norge AS | Wholesale & retail | 2002 |
| Sunny AS | Manufacturing | 2022 |
| Svehaug AS | Professional & scientific | 2016 |
| Svein Helges Eiendom AS | Real estate | 2013 |
| Svelland Eiendom AS | Real estate | 2018 |
| Syd-Vest AS | Real estate | 2001 |
| Sønmørinvest AS | | 2025 |
| Sørsten Utmark & Vilt AS | Agriculture & fishing | 2026 |
| T2 Byggelektro Da | Construction | 2000 |
| Taake AS | Agriculture & fishing | 2025 |
| Tangmoen AS | | 2020 |
| Tannlege Helgesen AS | Health & social care | 2018 |
| Tbmv Eiendom AS | Wholesale & retail | 2017 |
| Tela Eiendom AS | Real estate | 2003 |
| Tela Sag Og Høvleri AS | Manufacturing | 1994 |
| Telebygget Tynset AS | Real estate | 2019 |
| TF Dekkteam AS | Wholesale & retail | 2007 |
| The Hylens AS | Wholesale & retail | 2021 |
| The Lodge Trysil AS | Real estate | 2016 |
| Tolga- Og Tynsetdyrlegene SA | Professional & scientific | 2004 |
| Tomtegata Eiendom AS | Real estate | 2010 |
| Tonje Morønning AS | Other services | 2017 |
| TPH Eiendom AS | Real estate | 2025 |
| Trafikkskolesenteret Tynset AS | Education | 2010 |
| Trekonstruksjoner AS | Manufacturing | 1994 |
| Tron Eiendomsutvikling AS | Real estate | 2012 |
| Trude Nygard Johansen Holding AS | | 2026 |
| Trysilanlegg AS | Construction | 2019 |
| Tunna-Fåa Grunneierlag SA | Real estate | 1934 |
| Turoperatøren Hit & Dit AS | Administrative & support | 2007 |
| Turoperatøren Hit & Dit Da | Administrative & support | 2006 |
| Tymex AS | Information & communication | 2026 |
| Tynset Beitelag SA | Real estate | 2014 |
| Tynset Betong AS | Mining & quarrying | 1986 |
| Tynset Cafe & Bar AS | Hospitality | 2024 |
| Tynset Diesel AS | Other services | 2000 |
| Tynset Eiendom AS | Real estate | 1995 |
| Tynset Event AS | Administrative & support | 2021 |
| Tynset Farve Og Interiør AS | Wholesale & retail | 2003 |
| Tynset Fysioterapi Da | Health & social care | 2021 |
| Tynset Grafikkverksted Da | Education | 2015 |
| Tynset Graving Og Transport AS | Construction | 2015 |
| Tynset Hotell AS | Real estate | 2015 |
| Tynset Hotell Drift AS | Hospitality | 2016 |
| Tynset Invest AS | Real estate | 1998 |
| Tynset Jernvarehandel AS | Wholesale & retail | 2021 |
| Tynset Maskin Elektro AS | | 2007 |
| Tynset Maskinforretning Eiendom AS | Real estate | 1938 |
| Tynset Minipris AS | Wholesale & retail | 2000 |
| Tynset Nevrologiske Klinikk AS | Health & social care | 2007 |
| Tynset Optiske AS | Wholesale & retail | 1997 |
| Tynset Optiske Eiendom AS | Real estate | 2022 |
| Tynset Park Og Anlegg AS | Construction | 1995 |
| Tynset Servicesenter AS | Other services | 1991 |
| Tynset Smådyrkontor AS | Professional & scientific | 2017 |
| Tynset Takst AS | Professional & scientific | 2016 |
| Tynset Tannlegesenter AS | Health & social care | 2019 |
| Tynset Taxisentral SA | Transport & logistics | 2017 |
| Tynset Transport AS | Transport & logistics | 1990 |
| Tynset Tre Og Betong AS | Manufacturing | 1990 |
| Tynset Vaktselskap AS | Administrative & support | 2020 |