| Teleweb AS | Information & communication | 2018 |
| Telger AS | Construction | 2016 |
| Tell AS | Information & communication | 2024 |
| Telluz Iq AS | Information & communication | 2024 |
| Telum Consulting AS | Professional & scientific | 2009 |
| Tema Kapital AS | Manufacturing | 2005 |
| Tempelhof AS | Real estate | 2010 |
| Tempest Holding AS | | 2023 |
| Ten Miles AS | Professional & scientific | 2016 |
| Tenk Design AS | Information & communication | 2019 |
| Tenk Performance AS | Professional & scientific | 2025 |
| Tenners Venner AS | Health & social care | 2012 |
| Tenthai Massasje AS | Other services | 2025 |
| Teppeland AS | Wholesale & retail | 2011 |
| Teppeland Drammen AS | Wholesale & retail | 2008 |
| Teppeland Høvik AS | Wholesale & retail | 2002 |
| Terje Huse Invest AS | Real estate | 2005 |
| Terje Mile Holding AS | | 2026 |
| Ternen Maskinentreprenør AS | Construction | 2007 |
| Terraplan AS | Professional & scientific | 2019 |
| Tervo AS | Construction | 2026 |
| Tes Investment AS | Real estate | 2012 |
| Tesi Eiendom AS | Manufacturing | 1998 |
| Tess Sør AS | Wholesale & retail | 2016 |
| Tesverse AS | Wholesale & retail | 2016 |
| Texflow AS | Other services | 2026 |
| TF Connect AS | Professional & scientific | 2026 |
| TF Gold Holding AS | | 2025 |
| Tfauskanger Holding AS | Information & communication | 2020 |
| TGN Energy AS | Professional & scientific | 2020 |
| TH Døra AS | Construction | 2022 |
| TH Ressurs AS | | 2025 |
| TH Tjenester AS | Administrative & support | 2020 |
| Thamsgatens Parkeringshus AS | Transport & logistics | 2013 |
| Thamss Holding AS | Health & social care | 2021 |
| Thamss Medical AS | Health & social care | 2023 |
| The Brewery Gulskogen AS | Wholesale & retail | 2017 |
| The Bubble Lab AS | Hospitality | 2024 |
| The Change Fotterapi AS | Other services | 2022 |
| The Flow AS | Arts & recreation | 2023 |
| The Holding AS | Manufacturing | 2011 |
| The Junction AS | Wholesale & retail | 2015 |
| The Little House & Company Da | Wholesale & retail | 2015 |
| The Very Co. AS | Professional & scientific | 2025 |
| The Wats Company AS | Information & communication | 2018 |
| Thea Nor AS | Real estate | 2021 |
| Theada AS | Financial services | 2005 |
| Theemptybox AS | | 2024 |
| Thepoint Consulting AS | Professional & scientific | 2023 |
| Thermoflow Engineering AS | Professional & scientific | 2026 |
| Thia AS | Financial services | 2012 |
| Thielemann Consult AS | Professional & scientific | 2014 |
| Thielemann Holding AS | | 2023 |
| Thingstad Rune Transport AS | Transport & logistics | 2024 |
| Think Big Technologies AS | Manufacturing | 2021 |
| Thinn AS | Real estate | 2022 |
| Third Invest AS | Financial services | 2012 |
| Thomanda AS | Real estate | 2023 |
| Thomanda Holding AS | Real estate | 2005 |
| Thomas Al Holding AS | | 2022 |
| Thomas Gienke Prosjekt AS | Professional & scientific | 2018 |
| Thomas Sergeev Holding AS | | 2025 |
| Thorbjørn Stryken Invest AS | Real estate | 2005 |
| Thorjac AS | Financial services | 2007 |
| Thorne Larsen Holding AS | Health & social care | 2021 |
| Thornegata 22 AS | Real estate | 2020 |
| Thorrud Gård AS | Agriculture & fishing | 1997 |
| Thorsby AS | Professional & scientific | 2005 |
| Thorsen Holding AS | Real estate | 2012 |
| Thorsen Invest AS | Professional & scientific | 2016 |
| Thorstein Finnerud AS | Education | 2017 |
| Thrive Da | Professional & scientific | 2023 |
| THT Invest AS | | 2021 |
| Thunder-Holding AS | | 2024 |
| Thunderstorm Capital AS | | 2020 |
| Thunes & Hansen Tannteknikk AS | Health & social care | 2026 |
| Thunhaug Invest AS | Professional & scientific | 2013 |
| Tibia AS | | 2024 |
| Ticon Bangeløkka 2 AS | Real estate | 1994 |
| Ticon Bangeløkka 3 AS | Real estate | 2012 |
| Ticon Bangeløkka AS | Real estate | 2011 |
| Ticon Bragernes Atrium AS | Real estate | 2018 |
| Ticon Broen AS | Real estate | 2000 |
| Ticon Båthavn AS | Real estate | 2006 |
| Ticon Eiendom AS | Real estate | 2004 |
| Ticon Engersand Havn 14 AS | Real estate | 2011 |
| Ticon Engersand Havn 19 AS | Real estate | 2017 |
| Ticon Engersand Havn 7 AS | Real estate | 2011 |
| Ticon Engersand Havn Tomteselskap AS | Real estate | 2015 |
| Ticon Follestad 3 AS | Real estate | 2018 |
| Ticon Fosskvartalet AS | Real estate | 1989 |
| Ticon Gruppen AS | Real estate | 2004 |
| Ticon Invest AS | Real estate | 2004 |
| Ticon K145 AS | Real estate | 2007 |
| Ticon Utvikling AS | Real estate | 2008 |
| Tidemann Holding AS | Real estate | 2012 |
| Tiedemands AS | Hospitality | 2024 |
| Tigne Invest AS | | 2026 |
| Tilbedriften AS | Information & communication | 2022 |
| Timalu AS | Wholesale & retail | 2007 |