| Oppdalskjøla AS | Real estate | 2016 |
| Oppdalslaft AS | Construction | 2007 |
| Oppdalslam SA | Manufacturing | 2017 |
| Oppdalsmat AS | Manufacturing | 2015 |
| Oppdalsporten AS | Real estate | 1996 |
| Oppdalsporten Drift AS | Hospitality | 2023 |
| Oppdalstoppen 880 AS | Real estate | 2004 |
| Oppdalstoppen Invest AS | Real estate | 2008 |
| Opplev Oppdal AS | Arts & recreation | 1989 |
| Opplys - Oppdal Lysstøperi Da | Manufacturing | 2003 |
| Opplæringskontoret I Oppdal Og Rennebu SA | Education | 2016 |
| Oramac AS | Administrative & support | 2011 |
| Otretek AS | Manufacturing | 2007 |
| Otto Meisingset AS | | 2020 |
| Otto Oppdal AS | Real estate | 2017 |
| Parkus AS | Real estate | 2020 |
| Per Erik Ansnes Eiendom AS | Construction | 2005 |
| Per Grøseth AS | Financial services | 2005 |
| Pets 2 Rest AS | Other services | 1993 |
| Pimar AS | | 2018 |
| Pipeinpipe AS | Professional & scientific | 2026 |
| Profundus AS | Hospitality | 1995 |
| Propertec AS | Manufacturing | 2020 |
| Radio E6 AS | Information & communication | 2004 |
| Ramp Holding AS | | 2016 |
| Ramstad Maskin AS | Construction | 2010 |
| Rasco Holding AS | Construction | 2016 |
| Ravo Utvikling AS | Real estate | 2007 |
| Regnskap Ledelse AS | Administrative & support | 2017 |
| Resta Holding AS | | 2022 |
| Roar Sørlien Holding AS | | 2026 |
| Roger Røstad Holding AS | Manufacturing | 2024 |
| Rolf Kristian Mathisen AS | Health & social care | 2023 |
| Rolf Sverre Holum AS | Wholesale & retail | 2011 |
| Romis AS | Information & communication | 2021 |
| Romoline AS | Professional & scientific | 2019 |
| Rull Holding AS | | 2026 |
| Rune Hagen Invest AS | Professional & scientific | 2011 |
| Rune Kvalsnes Holding AS | | 2023 |
| Ryam AS | | 2026 |
| Ræsset Vasslag SA | Water & waste | 2007 |
| Røft AS | Real estate | 2020 |
| Rønningslia Holding AS | Agriculture & fishing | 2005 |
| Røstad Landbruksverksted AS | Manufacturing | 2005 |
| S & S Invest AS | Real estate | 2017 |
| S3B Holding AS | | 2025 |
| Sabrura Oppdal AS | Hospitality | 2021 |
| Sagtomta AS | Real estate | 2018 |
| Sandmoen AS | Professional & scientific | 2005 |
| Sara Nilsen AS | Wholesale & retail | 2020 |
| Savannah AS | Real estate | 2012 |
| Schevik Vaktmester Og Hytteservice AS | Administrative & support | 2026 |
| Scholten Holding AS | | 2025 |
| Selbekk Invest AS | Real estate | 2005 |
| Sensaqua AS | Professional & scientific | 2005 |
| Sentrumsbygg Oppdal AS | Real estate | 2016 |
| SHR Bygg AS | Construction | 2011 |
| SI40 Eiendom AS | Real estate | 2024 |
| Skaja AS | Agriculture & fishing | 2010 |
| Skarsem Vannverk SA | Water & waste | 2016 |
| Skifer Og Granitt Oppdal AS | Construction | 2016 |
| Skjøld Eiendom AS | Real estate | 2026 |
| Skjørdøla Vassverk SA | Water & waste | 1995 |
| Skreen & Stensrud Eiendom AS | Real estate | 2015 |
| Skreen AS | Administrative & support | 2005 |
| Skreen Eiendom AS | Real estate | 2015 |
| Skreen Transport & Utleie AS | Administrative & support | 2004 |
| Sky Invest AS | | 2020 |
| Skytterhuset SA | | 1992 |
| Sleipner Invest Holding AS | Financial services | 2015 |
| Smak Av Fjell SA | Professional & scientific | 2017 |
| Snydda AS | Information & communication | 2021 |
| Snøhetta Regnskap Oppdal AS | Professional & scientific | 2015 |
| Snøhetta Sikkerhet AS | Administrative & support | 2017 |
| Snøve Eiendom AS | Real estate | 2012 |
| Solberg Betong AS | Real estate | 2022 |
| Solgrenda AS | | 2016 |
| Sparebørsa Holding AS | | 2021 |
| Sportshuset AS | Real estate | 1989 |
| Stavåløkkja Øvre Vannverk SA | Water & waste | 2024 |
| Stein Røstad AS | Manufacturing | 2011 |
| Sten Design AS | Wholesale & retail | 2023 |
| Stenløkk Eiendom AS | Real estate | 2015 |
| Stensrud Bolig AS | Real estate | 2016 |
| Stensrud Invest AS | Real estate | 2006 |
| Stig Og Ståle Bygg Ans | Construction | 1993 |
| Stig Stenløkk Holding AS | Professional & scientific | 2016 |
| Storvik AS | Professional & scientific | 1987 |
| Strand Drift Oppdal AS | Agriculture & fishing | 2006 |
| Strand Eiendom Oppdal AS | Agriculture & fishing | 2005 |
| Strand Vognild Eiendom Da | Real estate | 2002 |
| Stubbanlia Vannlag SA | Water & waste | 2015 |
| Stuen Utvikling AS | Real estate | 2014 |
| Stuggu Invest AS | Real estate | 2012 |
| Stølen Private Barnehage SA | Education | 1988 |
| Svarthaugen Bygdeservice SA | Administrative & support | 2010 |
| Svarthaugen Viltområde SA | Real estate | 1993 |
| Svorunda Vannverk SA | Water & waste | 2001 |
| Swahili Coast Mission AS | Other services | 2016 |
| Syas Invest AS | Financial services | 2007 |