| Røros Takst AS | Real estate | 2015 |
| Røros Tomteselskap AS | Real estate | 1979 |
| Røros Trafikkskole AS | Education | 2024 |
| Røros Tweed AS | Manufacturing | 1976 |
| Røros Utleie AS | Administrative & support | 2022 |
| Røros Varme AS | Construction | 2015 |
| Røros Vekst AS | Real estate | 1991 |
| Røros Ventilasjon AS | Construction | 2026 |
| Røros VVS AS | Construction | 2000 |
| Røros-Is AS | Manufacturing | 2018 |
| Rørosbaker'N AS | Manufacturing | 2016 |
| Rørosbaker'N Eiendom AS | Real estate | 2013 |
| Rørosbanken Røros Sparebank | Financial services | 1842 |
| Rørosbarn AS | Wholesale & retail | 2020 |
| Rørosbua AS | Wholesale & retail | 2014 |
| Rørosfilm AS | Information & communication | 2024 |
| Rørosgård Grunneierlag SA | Real estate | 1997 |
| Røroshotellene AS | Hospitality | 2024 |
| Røroshytta AS | Manufacturing | 2003 |
| Rørosmat SA | Wholesale & retail | 1999 |
| Rørosmeieriet AS | Manufacturing | 2001 |
| Rørosmeieriet Eiendom AS | Real estate | 2026 |
| Rørosregionen Næringshage AS | Professional & scientific | 2006 |
| Rørosrein AS | Manufacturing | 2010 |
| Rørosteknikk AS | Administrative & support | 2001 |
| Rørosvidda Hotell AS | Hospitality | 1999 |
| Sagebro Group AS | Information & communication | 2021 |
| SBP AS | Professional & scientific | 2014 |
| Scan Eiendom AS | Real estate | 1990 |
| Sejm Invest AS | Real estate | 2011 |
| Shortcode Holding AS | Information & communication | 2025 |
| Sirkus Holding AS | Financial services | 2013 |
| Siv. Ing H Storli AS | Professional & scientific | 2005 |
| Skag Holding AS | | 2026 |
| Skancke AS | Other services | 1996 |
| Skanckegårdene AS | Real estate | 1970 |
| Skeidar Røros AS | Wholesale & retail | 2016 |
| Skjerdingstadgården Da | Real estate | 2019 |
| Skolert AS | Education | 2014 |
| Skott Holding AS | | 2025 |
| Skotts Maskin AS | Construction | 2006 |
| Slem Holding AS | | 2023 |
| Slettum Holding AS | Arts & recreation | 2010 |
| Snekkervollen Holding AS | Real estate | 2021 |
| Snøglimt Hud- Og Velvære AS | Other services | 2025 |
| Soloppgangen Helse Og Miljø AS | Wholesale & retail | 2000 |
| Sorken Bil Og Folie Ans | Other services | 2014 |
| Sport 1 Røros AS | Wholesale & retail | 2014 |
| Sporten Røros AS | Wholesale & retail | 2019 |
| Stega Holding AS | Real estate | 2020 |
| Stenbråttet Barnehage SA | Education | 1986 |
| Stensaas Eiendom AS | Real estate | 1990 |
| Stensaas Holding AS | | 2025 |
| Stensaas Reinsdyrslakteri AS | Manufacturing | 1989 |
| Sti AS | Hospitality | 2021 |
| Stop - Nordic Content Protection F.M.B.A Nuf | Other services | 2015 |
| Strickert Holding AS | | 2024 |
| Sverfolk Ans | Arts & recreation | 2007 |
| Tamnes Maskin AS | Construction | 2026 |
| Tamneshalvøen Invest AS | Wholesale & retail | 2005 |
| Tannlege Edvin Grådal AS | Health & social care | 1997 |
| Tannlege Magne Hofstad AS | Health & social care | 2026 |
| Telebygget Eiendom AS | Real estate | 2002 |
| Telegrafen Frisør AS | Other services | 2014 |
| Terje Lien Holding AS | | 2016 |
| The Folk Music Academy AS | Education | 2020 |
| The Nordic Fiddlers Bloc Da | Arts & recreation | 2016 |
| The Sweet 1 AS | Manufacturing | 2018 |
| Thorthor AS | Education | 2020 |
| Tina Sjøvold Holding AS | Other services | 2019 |
| Tollef Bredalsvei 6 AS | Real estate | 2014 |
| Toyota Slettum Bil AS | Wholesale & retail | 2010 |
| Training of Life AS | Health & social care | 1996 |
| Trekanten 2 AS | Real estate | 2005 |
| Troll Mushing AS | Wholesale & retail | 2009 |
| Trondheimsvegen 1 AS | Real estate | 2005 |
| Trygstad Bakeri Og Konditori AS | Manufacturing | 2012 |
| Tufta Eiendom AS | Real estate | 2008 |
| Tømrer Klas Sommer AS | Construction | 2017 |
| Tønset Holding AS | Real estate | 2016 |
| Ulmer AS | | 2019 |
| Ulrich Eiendom AS | Real estate | 2003 |
| Urdarbrunnr Invest AS | | 2023 |
| Ute Depot AS | Wholesale & retail | 2026 |
| Ute Depot AS | Wholesale & retail | 1997 |
| Vaa AS | Professional & scientific | 2020 |
| Varmbo Røros Entreprenør AS | Construction | 2012 |
| Vaskarryss AS | | 2023 |
| Vaskebjørn Bilpleie AS | Other services | 2015 |
| Ve Drift AS | Wholesale & retail | 2018 |
| Verket Røros AS | Real estate | 2009 |
| Vibe Management AS | Administrative & support | 2015 |
| Viermie AS | Energy | 2017 |
| Villmarka AS | Wholesale & retail | 2024 |
| Villmarka Holding AS | | 2025 |
| Vinterled Røros AS | Arts & recreation | 2016 |
| Visit Røros Og Østerdalen SA | Administrative & support | 2022 |
| Voi Voi Røros AS | Hospitality | 2025 |
| Ymse Eiendom AS | Real estate | 2024 |
| Ymse Holding AS | Real estate | 2023 |