| TNL Consulting AS | Professional & scientific | 2019 |
| To Hjerter AS | Wholesale & retail | 1997 |
| Tokahevi AS | Professional & scientific | 2005 |
| Tom Energi AS | Professional & scientific | 2021 |
| Tom Martins Service AS | Administrative & support | 2012 |
| Tommelomsk AS | Health & social care | 2022 |
| Tomra Europe AS | Manufacturing | 1998 |
| Tomra Horizon AS | Water & waste | 2023 |
| Tomra Sorting AS | Professional & scientific | 2000 |
| Tomra Systems ASA | Manufacturing | 1972 |
| Toneart AS | Education | 2008 |
| Tonje Ballesteros Invest AS | | 2025 |
| Tony Trefelling AS | Agriculture & fishing | 2018 |
| Topp Still AS | Construction | 2015 |
| Topp Still Utleie AS | Administrative & support | 2016 |
| Toppunktet AS | | 2024 |
| Torq Software Invest AS | Information & communication | 2023 |
| Tosu AS | Real estate | 2013 |
| Totall AS | Information & communication | 2019 |
| TPJ AS | | 2020 |
| TPL Holding AS | Information & communication | 2020 |
| Trafo Editions AS | Arts & recreation | 2025 |
| Trafo Frames AS | Manufacturing | 2025 |
| Trafo Kunstproduksjon AS | Arts & recreation | 2014 |
| Trampolin AS | Information & communication | 2019 |
| Tranbergkollen Invest AS | Financial services | 2015 |
| Tranquility AS | Real estate | 2020 |
| Transpetrol Shipping AS | Transport & logistics | 2024 |
| Transpetrol TM AS | Transport & logistics | 2002 |
| Transport Entreprenør AS | Transport & logistics | 1993 |
| Transportkvalitet AS | Professional & scientific | 2019 |
| Trappekompaniet AS | Wholesale & retail | 2008 |
| Trefelling.Com AS | Agriculture & fishing | 2010 |
| Trekanten Klokker Og Smykker AS | Wholesale & retail | 2005 |
| Trekanten Legesenter Asker AS | Health & social care | 2020 |
| Trellis AS | Information & communication | 2020 |
| TRG Trading Holding AS | | 2021 |
| Trier Tours AS | Professional & scientific | 1996 |
| Trocon AS | Professional & scientific | 2002 |
| Trollco Consulting AS | Professional & scientific | 2015 |
| Trollstua, Frelsesarmeens Barnehage I Asker AS | Education | 2022 |
| Trommenatten Invest AS | Financial services | 2009 |
| Trondo AS | | 2021 |
| Trym Holding AS | | 2018 |
| Trypro AS | Professional & scientific | 2022 |
| Trypro Holding AS | Professional & scientific | 2012 |
| Trøseid AS | Professional & scientific | 2015 |
| TS Håndverk AS | Construction | 2012 |
| Tshuva AS | Financial services | 2017 |
| Tuktuk Asker AS | Hospitality | 2021 |
| Tuktuk Thai Street Food Asker AS | Hospitality | 2025 |
| Turbobla Adventure AS | Administrative & support | 2021 |
| Turn the Tide AS | Information & communication | 2013 |
| Tusahe Holding AS | | 2026 |
| Tuvru AS | | 2023 |
| TV22 Utvikling AS | Real estate | 2021 |
| Twistedglass AS | Wholesale & retail | 1986 |
| TWS Holding AS | Professional & scientific | 2018 |
| Tyrihans Invest AS | Professional & scientific | 2005 |
| Tårnet AS | Real estate | 2017 |
| Tømrer M.Muggebye AS | Construction | 2025 |
| Tømrer Thomas AS | Construction | 1998 |
| Tømrerfirmaet Mæland & Christiansen AS | Construction | 2000 |
| Tømrerlandslaget AS | Construction | 2020 |
| Tømrermester Kristen Torp AS | Construction | 2014 |
| Tønsberg Næringspark Nord AS | Real estate | 2023 |
| Ubinvest AS | | 2024 |
| Ugb Holding AS | Financial services | 2008 |
| Uipath Norway AS | Information & communication | 2019 |
| Ultima Consult AS | Professional & scientific | 2025 |
| Ultima-Thule Nuf | Agriculture & fishing | 2010 |
| Ulven Hals Invest AS | | 2024 |
| Ulvenveien Utvikling AS | Real estate | 1993 |
| Undelstad Gård AS | | 2026 |
| Undelstadlia 27 AS | Real estate | 2016 |
| Underdog Adventures AS | Information & communication | 2017 |
| Ung Helse Klinikk AS | Health & social care | 2024 |
| Unicorn AS | | 2005 |
| Unicorns and Lions AS | Education | 2023 |
| Unik Engros AS | Wholesale & retail | 2020 |
| Unilink Software (Norway) AS | Information & communication | 2019 |
| Unique Eiendom AS | Real estate | 1998 |
| Universe Help AS | Health & social care | 2022 |
| Universemed AS | Other services | 2020 |
| Unlimited Media AS | Arts & recreation | 2017 |
| Utecomfort AS | Wholesale & retail | 2012 |
| Uteliv Oslo Invest AS | Hospitality | 2020 |
| Utenlandstjenesten AS | Professional & scientific | 2003 |
| V3R Holdings AS | | 2021 |
| Va Bene AS | Transport & logistics | 2025 |
| Vaagal Prosjekt AS | Professional & scientific | 2025 |
| Vabråten Invest AS | Professional & scientific | 2025 |
| Vadholmen Invest AS | Wholesale & retail | 2021 |
| Vadholmen Vann- Og Avløpslag SA | Water & waste | 2004 |
| Vadvin AS | Health & social care | 2015 |
| Vai AS | | 2026 |
| Vaja AS | Construction | 2013 |
| Vaktmester Berg AS | Administrative & support | 2025 |
| Vallgard AS | Wholesale & retail | 2026 |
| Valt Vani AS | Manufacturing | 2022 |