| Snakkom Da | Arts & recreation | 2025 |
| Soel AS | Wholesale & retail | 2022 |
| Softcomm AS | Wholesale & retail | 1996 |
| Sojuda Holding AS | | 2026 |
| Solgården Sideri AS | Agriculture & fishing | 2025 |
| Solid Rørlegger AS | Construction | 2017 |
| Solkysten Boligpartner AS | Construction | 2025 |
| Sollia Holding AS | Financial services | 2011 |
| Sona Invest AS | | 2023 |
| Soneva AS | Information & communication | 2026 |
| Sorknes Gård AS | Real estate | 1994 |
| Sorknes Holding AS | Real estate | 1992 |
| Source Code AS | Information & communication | 2020 |
| Sovial AS | | 2015 |
| Speedhunters Holding AS | | 2020 |
| Spes & Fides AS | Administrative & support | 2025 |
| Spirer AS | | 2025 |
| Sportagile AS | Wholesale & retail | 2003 |
| Sports Turf Management AS | Professional & scientific | 2017 |
| Srour AS | Real estate | 2025 |
| Stangeby Veien 1 AS | Real estate | 2016 |
| Stangebyveien 17 Newco AS | Real estate | 2025 |
| Stangebyveien 19 AS | Real estate | 2025 |
| Statwind AS | Construction | 2005 |
| Steinar Krauss AS | Health & social care | 2022 |
| Steinkompaniet AS | Manufacturing | 2024 |
| Steinkompaniet Holding AS | Manufacturing | 2024 |
| Steinkompaniet X Design AS | Wholesale & retail | 2025 |
| Stemme Og Tale AS | Health & social care | 2025 |
| Sterke Karer AS | Transport & logistics | 2019 |
| Stockit AS | Information & communication | 2017 |
| Stolt Invest AS | Real estate | 2019 |
| Storgata 17 AS | Real estate | 2023 |
| Storgaten 13B AS | Financial services | 2022 |
| Strategie AS | Professional & scientific | 1975 |
| Straton Eiendom I AS | Real estate | 2012 |
| Straton Eiendom II AS | Real estate | 2017 |
| Straton Holding AS | Real estate | 2019 |
| Stratus Holding AS | Information & communication | 2024 |
| Stu Holding AS | Financial services | 2005 |
| Studio Einang AS | Manufacturing | 2023 |
| Stålerød Holding AS | Wholesale & retail | 2024 |
| Sundal Marine AS | Wholesale & retail | 1998 |
| Sundal Offshore AS | Professional & scientific | 2010 |
| Sundal Team Invest AS | Manufacturing | 2005 |
| Sundal Yacht AS | Manufacturing | 2000 |
| Sundal Yacht Import AS | Wholesale & retail | 2012 |
| Svartskuren Investment Group AS | Wholesale & retail | 1987 |
| Svensrud Holding AS | Real estate | 2014 |
| Syn Invest AS | Construction | 2017 |
| Søndre Stiger Va Drift SA (Ssvad SA) | Water & waste | 2023 |
| T Guttormsen Gartneri AS | Agriculture & fishing | 1978 |
| Tafre Eiendom AS | Real estate | 2023 |
| Takst & Bygg AS | Real estate | 2023 |
| Tannlegene Aasen & Kvikstadhagen AS | Health & social care | 2021 |
| Tattoom AS | Financial services | 2015 |
| Tbrattås Holding AS | | 2025 |
| Techvalue Norway AS | Professional & scientific | 2010 |
| Teie Barber Shop AS | Other services | 2018 |
| Teie Elektro AS | Construction | 2016 |
| Teie Invest AS | | 2023 |
| Teie Sko AS | Wholesale & retail | 2024 |
| Teie Velvære AS | Other services | 2021 |
| Teie Økonomi & Regnskap AS | Professional & scientific | 2020 |
| Teiegården AS | Real estate | 1999 |
| Teiegården Parkering AS | Real estate | 2015 |
| Teielegene AS | Professional & scientific | 2023 |
| Tekmil AS | Professional & scientific | 2021 |
| Tembono Invest AS | Professional & scientific | 2019 |
| Tenvik Holding AS | Real estate | 2015 |
| Tenvik Hydraulikk Da | Manufacturing | 2003 |
| Terjesen Gruppen AS | | 2025 |
| Terra Heating AS | Construction | 1997 |
| Textura AS | Real estate | 1963 |
| TG Enterprise Group LLC Nuf | Wholesale & retail | 2025 |
| TG Enterprise Holding Ltd Nuf | Water & waste | 2025 |
| TH Malm Holding AS | | 2020 |
| Th-Invest AS | Other services | 2017 |
| The Grit AS | Education | 2018 |
| Thomas Rogstad Consulting AS | Information & communication | 2011 |
| Thorvest AS | Financial services | 2005 |
| Tigeric Holding AS | | 2019 |
| Tilkjørt AS | Hospitality | 2012 |
| Timber Bolig AS | Real estate | 2025 |
| Tinghauglegene Da | Health & social care | 2008 |
| Tjølsen Og Sønn Ans | Administrative & support | 2002 |
| Tjøme Rørservice AS | Wholesale & retail | 2003 |
| Tkar Invest AS | Financial services | 2016 |
| TM Helse AS | Health & social care | 2020 |
| TM Holdings AS | | 2019 |
| Tma Anlegg AS | | 2019 |
| Tma Holder AS | Financial services | 2023 |
| TMT Vekst AS | Financial services | 2021 |
| TN Rental AS | Administrative & support | 2025 |
| TNG Consulting AS | Professional & scientific | 2011 |
| Tokon AS | Administrative & support | 2010 |
| Tonk Invest AS | Financial services | 2016 |
| Top-Sail AS | Education | 2019 |
| Torbjørnrød Transport AS | Transport & logistics | 2009 |
| Tordenskjold Eiendom AS | Real estate | 2005 |