| TML Invest AS | Financial services | 2014 |
| TNB Porsgrunn AS | Wholesale & retail | 2002 |
| To Kusiner Anne Sidsel Schrumpf Og Anne Marie Holm Olsen Ans | Wholesale & retail | 1981 |
| Toba Utvikling AS | Real estate | 2018 |
| Toftdahl Kiropraktikk Og Fysioterapi AS | Health & social care | 2015 |
| Tollefsen Holding AS | Construction | 2012 |
| Tollmotunet Utvikling AS | Real estate | 2019 |
| Tollnes Utbygging AS | Real estate | 2019 |
| Tollskogvegen Utbygging AS | Construction | 2018 |
| Tom Dewey Holding AS | Financial services | 2005 |
| Tom Gjeruldsen Holding AS | Construction | 2005 |
| Tommy Gundersen Holding AS | | 2023 |
| Tonny Holding AS | Real estate | 2017 |
| Top Recruit AS | Administrative & support | 2014 |
| Top Secret Invest AS | | 2020 |
| Topptur Consulting AS | Construction | 2023 |
| Tor Helgesen Holding AS | | 2018 |
| Torsbergvegen 46 AS | Real estate | 2023 |
| Totalbygg Telemark AS | Construction | 2012 |
| Totalriv AS | Construction | 2019 |
| Touch Holding AS | Real estate | 2022 |
| Touch Soft AS | Wholesale & retail | 2010 |
| Touch Soft Technology AS | Information & communication | 2021 |
| Tovslid Holding AS | | 2019 |
| TR Holding AS | Wholesale & retail | 2020 |
| Trainee Vestfold Og Telemark AS | Professional & scientific | 2014 |
| Trappegruppen Holding AS | | 2025 |
| Tre Sombreros AS | Manufacturing | 2014 |
| Treasure Group AS | Wholesale & retail | 2023 |
| Trefeller'N AS | Agriculture & fishing | 2008 |
| Trefolket Da | Agriculture & fishing | 1998 |
| Trendhuset Jans Klær AS | Wholesale & retail | 2022 |
| TRG AS | Construction | 2005 |
| TRG Finans AS | | 2005 |
| Trokåsa Eiendom AS | Real estate | 2020 |
| Troli AS | Construction | 2005 |
| Trollbø Eiendom AS | Real estate | 1983 |
| Trollheim Holding AS | | 2024 |
| Trols AS | Real estate | 2005 |
| Trommedalen Invest AS | Real estate | 2019 |
| Troro Holding AS | | 2022 |
| Trosvik Boligutvikling AS | Real estate | 1988 |
| Trosvik Brygge 1 AS | Real estate | 2025 |
| Trosvik Brygge Bygg 1 AS | Real estate | 2025 |
| Trosvik Eiendom AS | Real estate | 2020 |
| Trosvik Utbygging AS | Professional & scientific | 2022 |
| Truckexport.No AS | Wholesale & retail | 2016 |
| Truma Holding AS | Other services | 2005 |
| Trygg Boligservice AS | Real estate | 1980 |
| Tryggavslutning AS | Information & communication | 2026 |
| Trønder'N AS | Construction | 2024 |
| TS Group AS | Administrative & support | 2005 |
| TS Site Services AS | Manufacturing | 1979 |
| TSG Holdco AS | Professional & scientific | 2008 |
| Ttoa Holding AS | | 2021 |
| TTS With Associates AS | Real estate | 2022 |
| Tubatse Invest AS | Financial services | 2005 |
| Tucasa AS | Real estate | 2006 |
| Tufte Eiendom AS | Real estate | 2004 |
| Tve Finans AS | Construction | 2023 |
| Tvedestrand Utvikling AS | Real estate | 2021 |
| Tveitanlia Bolig AS | Real estate | 2019 |
| Tvemo Invest AS | | 2025 |
| Twins Frisør AS | Other services | 2019 |
| Two Seasons Boardshop Da | Wholesale & retail | 2000 |
| TXP Holdings AS | | 2025 |
| Telemark Entreprenørservice AS | Construction | 1983 |
| Ulefossveien AS | Real estate | 1990 |
| Ulfsbakveien 2 AS | Real estate | 2010 |
| Ulrikkabakken Utvikling AS | Real estate | 2023 |
| Ulstrup Jansen Eiendom AS | Transport & logistics | 2016 |
| Undervannsentreprenøren AS | Construction | 2011 |
| Uni Eiendom AS | Real estate | 2019 |
| Uni Holding AS | | 2026 |
| Uni Tak AS | Construction | 2013 |
| Uni-Seals Norge AS | Wholesale & retail | 2023 |
| Univers AS | Information & communication | 2016 |
| Unlimit AS | Information & communication | 2018 |
| Upe AS | Real estate | 2026 |
| Urd AS | Health & social care | 1987 |
| Urdarbrønnen SA | Education | 2000 |
| Utesauna AS | Wholesale & retail | 2020 |
| Utsikten 1 AS | Real estate | 2019 |
| Uvdal Apartments AS | Real estate | 2020 |
| Uvdal Hytter AS | Real estate | 2019 |
| Uve Cleantech AS | Manufacturing | 2017 |
| Vaag AS | Real estate | 2021 |
| VAKSINE24 AS | Health & social care | 2021 |
| Val & Co AS | Professional & scientific | 2014 |
| Valenwave AS | Professional & scientific | 2024 |
| Vallermyrene Utvikling AS | Real estate | 2024 |
| Vandalai AS | Professional & scientific | 2021 |
| Vangen Welding AS | Manufacturing | 2015 |
| Varde Holding AS | Construction | 2015 |
| Vare-Trans Da | Transport & logistics | 2003 |
| Vedkommende AS | Wholesale & retail | 2019 |
| Vedvik Elektro AS | Construction | 2022 |
| Vei Og Maskintjenester AS | Transport & logistics | 2018 |
| Veldreveien AS | Construction | 2021 |
| Venari Eiendom AS | Real estate | 2024 |