| Terje Paulsen Transport AS | Transport & logistics | 2025 |
| Terje Paulsen Utleie AS | Administrative & support | 2025 |
| Terminalen Byscene AS | Arts & recreation | 2013 |
| Termon AS | Financial services | 2005 |
| Tero Holding AS | Real estate | 2011 |
| Ters AS | Financial services | 2017 |
| Tess Nord AS | Wholesale & retail | 1998 |
| Tetlie Holding AS | | 2024 |
| Teval Invest AS | Wholesale & retail | 2005 |
| TH Dale AS | Wholesale & retail | 1983 |
| Thai Kitchen & Catering AS | | 2018 |
| Thai Thai Ålesund AS | Hospitality | 2020 |
| The Final AS | | 2015 |
| The Grape Escape AS | Wholesale & retail | 2025 |
| The Maritime Training Company AS | Education | 2024 |
| The North West AS | Administrative & support | 2017 |
| The Rudi Group AS | | 2024 |
| Theodyne AS | Professional & scientific | 2016 |
| Thermoplan AS | Professional & scientific | 2006 |
| Theserac AS | Professional & scientific | 2016 |
| Thomas Frøysa AS | Information & communication | 2020 |
| Thomas Stølen Holding AS | | 2026 |
| Thomir Invest AS | Information & communication | 2024 |
| Thonipa AS | Wholesale & retail | 2002 |
| Thor Falkevik AS | Construction | 1981 |
| Thor Invest AS | | 2016 |
| Thorir.Photo AS | Professional & scientific | 2016 |
| Thormax AS | Wholesale & retail | 2009 |
| THR Eiendom AS | Real estate | 2020 |
| THR Holding 1 AS | Agriculture & fishing | 2018 |
| THS Holding AS | Professional & scientific | 2021 |
| Thunem Holding AS | | 2018 |
| Thyri Holding AS | Financial services | 2021 |
| Tid Boligutvikling AS | Construction | 2017 |
| Tid Holding AS | Construction | 2003 |
| Tida Holding AS | Real estate | 2018 |
| Tigertank AS | Real estate | 2017 |
| Tikal Utvikling AS | Real estate | 2011 |
| Tilix AS | | 2023 |
| Tind Kapital AS | Financial services | 2020 |
| Tind Regnskap AS | Professional & scientific | 2021 |
| Tindar AS | | 2025 |
| Tinde Advokatfirma AS | Professional & scientific | 2017 |
| Tinghuset Bensin & Service AS | Wholesale & retail | 1983 |
| Tingstad AS | Wholesale & retail | 1991 |
| Tingvollvågen Eiendom AS | Real estate | 2021 |
| Tiny Town Play Café AS | Hospitality | 2025 |
| TJ Bygg AS | Construction | 2009 |
| TK Kapital AS | | 2021 |
| TK Med AS | Health & social care | 1993 |
| TK Moa AS | Wholesale & retail | 2006 |
| TKP Ultrahøytrykk AS | Administrative & support | 1996 |
| TLN Invest AS | Professional & scientific | 2016 |
| TM Media Team Ans | Professional & scientific | 2003 |
| TM Vandberg Holding AS | | 2022 |
| TN Consulting AS | Professional & scientific | 2020 |
| Tobo Maskin AS | Construction | 2022 |
| Tollbugt 6 Ans | Real estate | 1985 |
| Tolos AS | Real estate | 2012 |
| Tomaso AS | Real estate | 2006 |
| Tomatigu AS | | 2025 |
| Tomm AS | | 2022 |
| Tommeliten Fus Barnehage AS | Education | 2019 |
| Tomra Eiendom AS | Real estate | 2026 |
| Tone Molnes AS | Professional & scientific | 2023 |
| Tonjes Mathjørne AS | Wholesale & retail | 2019 |
| Tonningsgate 23 AS | Real estate | 1983 |
| Topptur Holding AS | | 2020 |
| Toppturing AS | Administrative & support | 2018 |
| Tor AS | Information & communication | 2005 |
| Tore Florvaag AS | Financial services | 2018 |
| Torill's Clinique Da | Health & social care | 1995 |
| Tornes Eiendom AS | Real estate | 2023 |
| Torpe AS | Real estate | 2021 |
| Torvløysa Invest AS | Financial services | 2013 |
| Torvmyra Hyttefelt SA | Real estate | 2014 |
| Torvteigen Barnehage AS | Education | 2023 |
| Total Consult AS | Professional & scientific | 1999 |
| TPN Holding AS | Real estate | 2005 |
| Tra Holding AS | | 2024 |
| Traa Invest AS | Financial services | 2006 |
| Trading International AS | Wholesale & retail | 1998 |
| Trainee Sunnmøre SA | Administrative & support | 2025 |
| Tramp AS | Professional & scientific | 2014 |
| Transport 24 AS | Transport & logistics | 2018 |
| Tranvåg Invest AS | | 2013 |
| Tranvåg Maritime AS | Education | 2008 |
| Tremont AS | Construction | 2020 |
| Tren Invest AS | | 2006 |
| Trestjerners AS | Professional & scientific | 2025 |
| TRH AS | Construction | 1987 |
| Triangelgaarden AS | Real estate | 2005 |
| Trio Spedisjon AS | Transport & logistics | 2023 |
| Triple Diamond Software Nuf | Information & communication | 2009 |
| Triplenine Sales Nuf | Wholesale & retail | 2019 |
| Trips of Norway Holding AS | Administrative & support | 2024 |
| Trips of Norway Vip AS | Administrative & support | 2025 |
| Trivsel Og Utvikling AS | Hospitality | 1994 |
| Trodalen Skogsveglag | Real estate | 2004 |
| Trollbotn AS | Professional & scientific | 2022 |