| Reinertsen New Energy AS | Professional & scientific | 2017 |
| Reinfjord Holding AS | | 2018 |
| Reinholdt AS | Wholesale & retail | 2005 |
| Reisevaksiner Trondheim AS | Health & social care | 2000 |
| REISEVERT1 AS | Administrative & support | 2025 |
| Reita AS | | 2020 |
| Reitan AS | Wholesale & retail | 2013 |
| Reitan Eiendom AS | Real estate | 2015 |
| Reitan Eiendom Drift AS | Real estate | 1997 |
| Reitan Holding AS | | 2020 |
| Reitan Invest AS | | 2018 |
| Reitangruppen AS | | 2020 |
| Reiten Kapital AS | | 2024 |
| Reklamebyrået A3 Ans | Professional & scientific | 1992 |
| Rekol Eiendom AS | Real estate | 2023 |
| Rekol Prosjekt 3 AS | Real estate | 2024 |
| Rekol Prosjekt 6 AS | | 2025 |
| Rekol Prosjekt 7 AS | | 2025 |
| Relax AS | Other services | 2005 |
| Relevio AS | Health & social care | 2021 |
| Reli Os AS | Real estate | 2008 |
| Relog AS | Real estate | 2021 |
| Relog Drift AS | Real estate | 2015 |
| Relog Energy AS | Real estate | 2010 |
| Relog Invest AS | Real estate | 2021 |
| Remember Me Holding AS | | 2018 |
| Remy Holding AS | Hospitality | 2014 |
| Remyra Eiendom AS | Real estate | 2014 |
| Ren Bil Trondheim AS | Other services | 2001 |
| Ren Energi AS | Professional & scientific | 2001 |
| Ren Oppdal AS | Real estate | 2006 |
| Ren Risvollan AS | Real estate | 2007 |
| Renate Syltern Invest AS | Real estate | 2020 |
| Renbalanse AS | Health & social care | 2022 |
| Renbygda AS | Real estate | 2013 |
| Rendal Fysioterapi AS | Health & social care | 2021 |
| Rendall AS | | 2023 |
| Renee Fagerhøi AS | Hospitality | 2022 |
| Rengjøringsteknikk AS | Administrative & support | 1992 |
| Renh Fosnagaten 12 AS | Real estate | 2017 |
| Renh Granåsen AS | Real estate | 2012 |
| Renh Holding AS | Real estate | 2017 |
| Renh Risvollan Park AS | Real estate | 2010 |
| Renholdsgrossisten Norge AS | Wholesale & retail | 2021 |
| Renraskbilvask AS | Other services | 2026 |
| Rent & Fint AS | Administrative & support | 2024 |
| Rent 4 You AS | Real estate | 1958 |
| Rent AS | Administrative & support | 2020 |
| Rent Miljø Holding AS | Administrative & support | 2005 |
| Rent Miljø Renhold AS | Administrative & support | 1997 |
| Rentalgruppen AS | Real estate | 2018 |
| Rentida AS | Administrative & support | 2025 |
| Reodor Felgen Invest AS | Professional & scientific | 2020 |
| Repiro AS | Professional & scientific | 2026 |
| Reppe Bolig AS | Real estate | 2019 |
| Reppe Eiendom AS | Real estate | 2007 |
| Reppe Utbygging AS | Real estate | 2013 |
| Repslagergården AS | Real estate | 2022 |
| Reselka Eiendom AS | Real estate | 2018 |
| Reserve Holding AS | | 2023 |
| Residential Development Fund 1 AS | | 2020 |
| Resirk AS | Wholesale & retail | 2026 |
| Resiva AS | Transport & logistics | 2026 |
| Resko AS | Professional & scientific | 1953 |
| Resonanz AS | Health & social care | 2025 |
| Resource AS | Professional & scientific | 2021 |
| Resource Holding AS | Professional & scientific | 2011 |
| Respro AS | Professional & scientific | 2021 |
| Ressem Holding AS | | 2021 |
| Restatus AS | Wholesale & retail | 2023 |
| Restaurant Da Vinci AS | Hospitality | 2005 |
| Restaurant Sikring Da | Administrative & support | 1998 |
| Restaurantdrifting AS | Professional & scientific | 2011 |
| Restauranter I Trondheim AS | Hospitality | 2016 |
| Restbo AS | Wholesale & retail | 2026 |
| Rethink Retail AS | Administrative & support | 2020 |
| Retold AS | Professional & scientific | 2022 |
| Retraze AS | Information & communication | 2017 |
| Retriever Music Group AS | Information & communication | 2020 |
| Retriever Publishing AS | Information & communication | 2026 |
| Retro AS | Wholesale & retail | 1997 |
| Retro Bergen AS | Wholesale & retail | 2004 |
| Retro Kristiansand AS | Wholesale & retail | 2004 |
| Retro Nordre AS | Wholesale & retail | 2001 |
| Rett Hjem Arkitekter AS | Professional & scientific | 2012 |
| Rett Hjem Bolig AS | Construction | 2014 |
| Rett Regnskap AS | Professional & scientific | 2016 |
| Rett Vei AS | Professional & scientific | 2025 |
| REV1 AS | | 2017 |
| Revelare Partners AS | Professional & scientific | 2013 |
| Revholmen AS | Wholesale & retail | 2023 |
| Revir Interiør AS | Professional & scientific | 2007 |
| Revisjon Og Råd AS | Professional & scientific | 2002 |
| Revisjonsfirmaet Arne J Buvik AS | Professional & scientific | 1996 |
| Revisjonsfirmaet Einersen AS | Professional & scientific | 2024 |
| Revisjonsfirmaet Leif Langø AS | Professional & scientific | 1995 |
| Revisjonskompaniet Midt-Norge AS | Professional & scientific | 2002 |
| Revisorfirma Ulf Strande AS | Professional & scientific | 1998 |
| Revive AS | Wholesale & retail | 2024 |
| Revsnes Holding AS | Financial services | 2016 |