| Ramazini AS | Health & social care | 1994 |
| Ranheim Apartments AS | Real estate | 2018 |
| Ranheim AS | | 2025 |
| Ranheim Bilservice AS | Other services | 2018 |
| Ranheim Byggpartner AS | Construction | 2014 |
| Ranheim Dyreklinikk AS | Professional & scientific | 2017 |
| Ranheim Legesenter AS | Health & social care | 2023 |
| Ranheim Næringspark AS | Real estate | 2017 |
| Ranheim Paper & Board AS | Manufacturing | 1918 |
| Ranheim Parkering AS | Real estate | 2020 |
| Ranheim Rørservice AS | Construction | 2019 |
| Ranheimsvegen 130 AS | Real estate | 2007 |
| RCT - Import Norge AS | Wholesale & retail | 2022 |
| Redpanda Holding AS | | 2025 |
| Reitan Lykke Invest AS | Real estate | 2008 |
| Ren Fasade AS | Administrative & support | 2021 |
| Reppe Andelslandbruk SA | Agriculture & fishing | 2017 |
| Reppe Auto AS | Wholesale & retail | 2020 |
| Reppe Nordre AS | Real estate | 2017 |
| Reppevegen 61-67 Veilag SA | Real estate | 2018 |
| Reppeåsen Maskin AS | Administrative & support | 2010 |
| Resman Technology AS | Professional & scientific | 2025 |
| Restaurant Romantica AS | Hospitality | 2015 |
| Rhyakva AS | Agriculture & fishing | 2018 |
| Rije Holding AS | Financial services | 2015 |
| Rikke Bragstad AS | | 2025 |
| Ril Spillerinvest 1 AS | | 2025 |
| Rivi Holding AS | Real estate | 2018 |
| Riw AS | Manufacturing | 2025 |
| RKH AS | Professional & scientific | 2022 |
| RKL Invest AS | Financial services | 2008 |
| Roald Brevik Holding AS | Real estate | 2011 |
| Robatoli Holding AS | Administrative & support | 2020 |
| Ronæss AS | Manufacturing | 1999 |
| Rosmo Invest AS | | 2024 |
| Rost Holding AS | Administrative & support | 2005 |
| Rosten Holding AS | Health & social care | 2021 |
| Rosvoll AS | Information & communication | 2018 |
| Rotbregd Holding AS | | 2021 |
| Rukundo AS | Transport & logistics | 2026 |
| Rune Solberg AS | Professional & scientific | 2026 |
| Rune Wæraas Holding AS | Wholesale & retail | 2005 |
| Ryds Holding AS | | 2017 |
| Rødven AS | Professional & scientific | 2005 |
| Rønningsbakken 25 AS | Real estate | 2005 |
| Rørleggersenteret Trondheim AS | Construction | 2013 |
| S-Ab Holding AS | | 2026 |
| S. Kristiansen Holding AS | Real estate | 2005 |
| S.R Invest AS | | 2024 |
| Safe Service Trondheim Da | Administrative & support | 2002 |
| Sagstad Eigedom AS | Real estate | 2024 |
| Salvesen Sigma AS | | 2025 |
| Samaheto AS | Real estate | 2006 |
| Sandberg Larsen Invest Limited Nuf | Information & communication | 2010 |
| Sandvik Consulting AS | Information & communication | 2022 |
| Sandvik Coromant AS | Manufacturing | 1989 |
| Sanmia Holding AS | Financial services | 2015 |
| Sbgnj AS | Wholesale & retail | 2024 |
| Scandi Car AS | Administrative & support | 2018 |
| Secure Holding AS | Financial services | 2011 |
| Seife AS | | 2025 |
| Selsbakkvegen 75 AS | Real estate | 2020 |
| Senas Utleie AS | Administrative & support | 2024 |
| Sep Holding AS | Real estate | 2005 |
| Sgull Invest AS | | 2023 |
| Shakti AS | Financial services | 2014 |
| Sigernes Sørlie AS | | 2025 |
| Siggerud Geo Services AS | Professional & scientific | 2005 |
| Simeda Invest AS | Administrative & support | 2017 |
| Singstad Holding AS | Construction | 2021 |
| Sinvest AS | Financial services | 2013 |
| Sisimar AS | Professional & scientific | 2022 |
| Sjøskogbekken Fus Barnehage AS | Education | 2018 |
| Skavdal Invest AS | | 2019 |
| Skillhouse AS | Administrative & support | 2002 |
| Skinnvest Invest AS | Administrative & support | 2005 |
| Skjermvegen 34 AS | Real estate | 2018 |
| Skjetne Invest AS | Financial services | 2015 |
| Skjold Service AS | Professional & scientific | 2020 |
| Skoglund Worldwide Infosystems AS | Professional & scientific | 2005 |
| Sky Finans Holding AS | | 2025 |
| Slettahjell Holding AS | Real estate | 2022 |
| SMC Holding AS | | 2016 |
| Småvikan Eiendomsutvikling AS | Real estate | 2023 |
| Snekkeroppdrag Leif Åge Smedhaug AS | Construction | 2022 |
| Softsense AS | Information & communication | 2021 |
| Solausi AS | Professional & scientific | 2019 |
| Soldernes AS | | 2025 |
| Solit AS | Information & communication | 2026 |
| Soradin Holding AS | | 2021 |
| Sperans AS | Professional & scientific | 2022 |
| Spiseute AS | Information & communication | 2026 |
| SSG Capital AS | | 2023 |
| ST Finans AS | Real estate | 2017 |
| Stadhav Eigedomsselskap AS | Real estate | 2018 |
| Stallheim Invest AS | Real estate | 2005 |
| Steadfast Holding AS | | 2024 |
| Stein-Interiør AS | Manufacturing | 2008 |
| Stejerr Invest AS | Financial services | 2008 |
| Stepstone Holding AS | Real estate | 2017 |