| Stathelle Auto Eiendom AS | Real estate | 2002 |
| Stathelle Eiendom AS | Real estate | 2007 |
| Stathelle Glass-Service AS | Construction | 2019 |
| Stathelle Marina AS | Wholesale & retail | 1983 |
| Stathelle Marina Drift AS | Wholesale & retail | 2004 |
| Stathelleveien 201 AS | Real estate | 2012 |
| Sten Kristiansen Pma | Construction | 2007 |
| Sti - Mar Holding AS | Real estate | 2011 |
| Stig Jacobsen Holding AS | Real estate | 2011 |
| Stoa Investering AS | Real estate | 2005 |
| Stokkebakken Vertshus AS | Hospitality | 1998 |
| Storegga-Senteret Da | Professional & scientific | 1996 |
| Strandgata 16B AS | Real estate | 2018 |
| Strandgata Blomster Og Interiør AS | Wholesale & retail | 2016 |
| Strandgaten 11 - Stathelle AS | Professional & scientific | 2009 |
| Strandsletta Båthavn Og Camping AS | Hospitality | 2021 |
| Strømtangvegen 20 AS | Real estate | 2014 |
| Strømtangvegen 22 AS | Real estate | 2014 |
| Svendsen Eie Industriservice AS | Manufacturing | 2025 |
| Swallet AS | Information & communication | 2025 |
| Systemhuset Episteme AS | Information & communication | 1990 |
| Sørø Taksering AS | Real estate | 2023 |
| Sørøst Bygg Og Varme AS | Wholesale & retail | 2012 |
| Sørøst Eiendomsutvikling AS | Real estate | 2020 |
| T. a. Baann Holding AS | Financial services | 2005 |
| T.E.S Forvaltning AS | Financial services | 2012 |
| Takbarge AS | Administrative & support | 2018 |
| Tangen-Bygg AS | Construction | 2022 |
| Tangen-Bygg AS | Construction | 2008 |
| Tangen-Holding AS | Real estate | 2022 |
| Target by Beck AS | Professional & scientific | 2025 |
| TB Consulting AS | Professional & scientific | 2016 |
| Tckc Holding AS | Financial services | 2012 |
| Tdi Invest AS | Professional & scientific | 2016 |
| Team Armering AS | Construction | 2016 |
| Teb Consult AS | Professional & scientific | 2018 |
| Techal AS | Information & communication | 2015 |
| Tegdal Vann- Og Avløpslag SA | Water & waste | 2011 |
| Teknobingo Stathelle AS | Arts & recreation | 1995 |
| Telemark Bakeri AS | Manufacturing | 2019 |
| Telemark Bilutsalg AS | Wholesale & retail | 2019 |
| Telemark Holding AS | | 2026 |
| Telemark Rørfornying AS | Construction | 2025 |
| Telemark Snekker Tjenester AS | Construction | 2023 |
| Telemark-Drift AS | Administrative & support | 2022 |
| Telemark-Svingen AS | Hospitality | 1996 |
| Tellefsen AS | Construction | 2008 |
| Tellefsen Invest AS | Real estate | 2009 |
| Temperert AS | Construction | 2023 |
| Terje Welle Busk & Co Lydstudio Og Musikkhandel | Information & communication | 1975 |
| Termotech Eriksen AS | Construction | 2014 |
| The Catsharks Da | Arts & recreation | 2023 |
| Thomas Haukedal AS | Wholesale & retail | 2024 |
| Thor R Nilsen AS | Wholesale & retail | 1981 |
| Thorsberg Invest AS | | 2019 |
| Thorsen Sagbruk AS | Real estate | 1985 |
| Thyholding AS | | 2024 |
| Tirilltoppen Barnehage Bamble SA | Education | 1989 |
| Titan Eiendom AS | Real estate | 2021 |
| Titan Eiendomsforvaltning AS | Administrative & support | 2021 |
| Titan Software AS | Information & communication | 2019 |
| Titan-Holding AS | Administrative & support | 2020 |
| TJL Holding AS | | 2025 |
| TM Catering AS | Hospitality | 2025 |
| Tmms Invest AS | | 2020 |
| Todco AS | Professional & scientific | 2005 |
| Tofu Holding AS | Professional & scientific | 2018 |
| Tombre AS | Professional & scientific | 2020 |
| Top Crew AS | Administrative & support | 2020 |
| Touch of Crazy AS | Arts & recreation | 2012 |
| Transportsentralen Stathelle SA | Transport & logistics | 1962 |
| Trimotech AS | Professional & scientific | 2014 |
| TRL Ekstrand Holding AS | Real estate | 2011 |
| Trolldalen Forvaltning AS | Real estate | 2024 |
| Trond a Kittilsen Shipping AS | Transport & logistics | 1992 |
| Trond Arne Jensen AS | Real estate | 2023 |
| Trond Ness Pedersen Holding AS | | 2022 |
| Trosby Sag & Transport AS | Wholesale & retail | 2005 |
| Trosbygården AS | Real estate | 2021 |
| Truck & Marine Service AS | Manufacturing | 2007 |
| Trude Westøl AS | Financial services | 2005 |
| Trygt AS | Health & social care | 2022 |
| Trymor Trading Da | Wholesale & retail | 1996 |
| Tuddalalpin AS | Agriculture & fishing | 2017 |
| Tuftheim Consulting AS | Professional & scientific | 2005 |
| Tømrer Max Gill AS | Construction | 2010 |
| Uab Litana Construction Nuf | Construction | 2025 |
| Ultratur På Kaasa Gård AS | Arts & recreation | 2017 |
| Umbilicus Eiendom AS | Real estate | 2014 |
| Umu Invest AS | | 2025 |
| Uni Tjenester AS | Construction | 2026 |
| Us Parts Supply AS | Wholesale & retail | 2014 |
| Ut Døra AS | Information & communication | 2022 |
| Utskauen AS | Information & communication | 2005 |
| V. Madsen Holding AS | Construction | 2005 |
| Valentinas Musikkbar AS | Hospitality | 2012 |
| Valle Bygg Og Vedlikehold AS | Construction | 2007 |
| Valle Båthavn AS | Manufacturing | 2005 |
| Valle Båtopplag AS | Manufacturing | 2012 |
| Vallekjærveien SA | Real estate | 2014 |