| Sørbyøya Hestesenter AS | Arts & recreation | 2021 |
| T Boye Pedersen AS | Real estate | 1997 |
| T Kristensen AS | | 2024 |
| T L Holding AS | Manufacturing | 1988 |
| T Og M Invest AS | Wholesale & retail | 2005 |
| T-Tak AS | Construction | 2016 |
| T. Almankås Holding AS | Construction | 2020 |
| T.I.M.Holding AS | Wholesale & retail | 2007 |
| T.Tveiten Invest AS | Health & social care | 2005 |
| Ta Group AS | Professional & scientific | 2022 |
| Ta Kapital AS | Wholesale & retail | 2024 |
| TA2 Invest AS | Manufacturing | 2008 |
| Tadam AS | Hospitality | 2020 |
| Tah Consulting AS | Professional & scientific | 2023 |
| Tailwind AS | Information & communication | 2009 |
| Takfjord AS | Construction | 2025 |
| Talkie Walkie AS | Wholesale & retail | 2020 |
| Talmoen Holding AS | | 2023 |
| Tamnes Holding AS | | 2025 |
| Tangenodden Va-Lag SA | Water & waste | 1997 |
| Tannklinikken Bøvre & Co AS | Health & social care | 2012 |
| Tannklinikken Marisol & Kaldheim AS | Health & social care | 2018 |
| Tannklinikken Marisol AS | Health & social care | 2005 |
| Tannlege Annette Bøvre AS | Health & social care | 2023 |
| Tannlege Christian Røsjorde AS | Health & social care | 2021 |
| Tannlege Karl Styren Tangen AS | Health & social care | 2012 |
| Tannlege Kristian Solheim AS | Health & social care | 2022 |
| Tannlege Kristin Aanderud-Larsen AS | Health & social care | 1999 |
| Tannlege Paul Taraldsen AS | Health & social care | 1989 |
| Tannpleier Minna Vale Sæter AS | Health & social care | 2020 |
| Tapet & Malercompaniet AS | Construction | 2006 |
| TARGET365 AS | Information & communication | 2017 |
| Tariel AS | Real estate | 2012 |
| Tauro Holding AS | | 2023 |
| Tauro Mogan AS | Real estate | 2012 |
| TB Finstad AS | Education | 2025 |
| TB Montasje AS | Construction | 2014 |
| TBN Holding AS | Financial services | 2007 |
| TBP Fysio AS | Health & social care | 2026 |
| Tci Holding AS | Professional & scientific | 2000 |
| TD Fellestjenester AS | Professional & scientific | 2007 |
| Te Eiendom AS | Administrative & support | 2006 |
| Team Entreprenør AS | Construction | 2004 |
| Team Hansen Consult AS | Information & communication | 2014 |
| Team Security AS | Administrative & support | 2007 |
| Team Treningssenter AS | Arts & recreation | 2006 |
| Teammate AS | Wholesale & retail | 2011 |
| Technet Consulting AS | Information & communication | 2013 |
| Techno AS | | 2021 |
| Technodisplay AS | Manufacturing | 1994 |
| Technomek AS | Manufacturing | 2013 |
| Techops AS | Professional & scientific | 2021 |
| Techytypes AS | Information & communication | 2020 |
| Teddy Elektro AS | Construction | 1994 |
| Tegn.Tv AS | Information & communication | 2021 |
| Teknomed AS | Manufacturing | 2001 |
| Teknovekst AS | Professional & scientific | 2021 |
| Teknovekst Invest AS | Professional & scientific | 2020 |
| Telecom & IT Megleren AS | Wholesale & retail | 2024 |
| Teledge AS | Professional & scientific | 2019 |
| Telt Og Fritid AS | Wholesale & retail | 1997 |
| Telttreff AS | Administrative & support | 2024 |
| Tember Holding AS | | 2005 |
| Tempo Eiendom AS | Real estate | 2012 |
| Tempo Legesenter Da | Health & social care | 2005 |
| Ten Holdingselskap AS | | 2026 |
| Teorimester AS | Information & communication | 2023 |
| Terje Bergskås Holding AS | | 2019 |
| Terje Bjanger AS | Construction | 2011 |
| Terje Invest AS | Information & communication | 2013 |
| Terki AS | Information & communication | 2024 |
| Terki Holding AS | Information & communication | 2024 |
| Terland Holding AS | Real estate | 2019 |
| Termoenergi Norge AS | Professional & scientific | 2014 |
| Termograferings Teknikk AS | Construction | 1999 |
| Tesa AS | Wholesale & retail | 2003 |
| Testsiden Ans | Wholesale & retail | 1999 |
| Tfo Holding AS | | 2019 |
| Tg-Invest AS | Real estate | 2018 |
| Th-Service AS | Wholesale & retail | 2019 |
| Thai Aroy Dee AS | Hospitality | 2022 |
| The Art Gallery Cafe Ans | Hospitality | 2000 |
| The Note AS | Hospitality | 2017 |
| The Vanilla Remedy AS | Wholesale & retail | 2020 |
| Theak Invest AS | Financial services | 2005 |
| Theotokopoulou AS | Real estate | 2018 |
| Thinghaugen AS | Hospitality | 2018 |
| Think Big AS | Wholesale & retail | 2023 |
| Thomas Olafsen Invest AS | Financial services | 2013 |
| Thomas Solberg Holding AS | Real estate | 2016 |
| Thor Dahl Management AS | Transport & logistics | 1996 |
| Thor Dahlsgate 1-5 AS | Real estate | 2017 |
| Thor Dahlsgate 9 AS | Real estate | 2006 |
| Thor Sykkel Sport AS | Real estate | 1992 |
| Thorni AS | Real estate | 1983 |
| Thorsholm Eiendomsdrift AS | Real estate | 1990 |
| Thorstein Hansens Eiendomsselskap AS | Real estate | 1975 |
| Thorvalda Holding AS | Professional & scientific | 2005 |
| Thorøya Båthavn AS | Arts & recreation | 1996 |
| Thuja Invest AS | | 2020 |