| Sørgen Holding AS | | 2021 |
| Sørlie-Sannes Dagligvare AS | Wholesale & retail | 2016 |
| Søte Drømmer AS | Wholesale & retail | 2011 |
| Sønes Invest A/S | Real estate | 1986 |
| T & I Invest AS | Real estate | 2006 |
| T 11 Bolig AS | Real estate | 2018 |
| T 11 Gjøvik AS | Real estate | 2018 |
| T-R Eiendom AS | Real estate | 2016 |
| T-Vekst AS | Financial services | 2008 |
| T.S. Johnsen Invest AS | Financial services | 2017 |
| T.Skaar | Construction | 2013 |
| T8 Eiendom AS | Real estate | 2005 |
| Tab Holding AS | | 2021 |
| Taf Invest AS | Financial services | 2014 |
| Takstcon AS | Professional & scientific | 2014 |
| Taksthuset Innlandet AS | Real estate | 2020 |
| Tal Capital AS | Real estate | 2021 |
| Tald Holding AS | Financial services | 2005 |
| Tananua AS | Real estate | 2006 |
| Tangen Konsult AS | Health & social care | 2023 |
| Tanngarden Eiendom Dokka AS | Real estate | 2017 |
| Tannlege Atle Førde AS | Health & social care | 2014 |
| Tannlege Cathrine Gudding AS | Health & social care | 2021 |
| Tannlege Daniel Nordhaug AS | Health & social care | 2017 |
| Tannlege Egil Hvalby AS | Health & social care | 2006 |
| Tannlege Heidi Flatebø AS | Health & social care | 2022 |
| Tannlege Hvalby AS | Health & social care | 2021 |
| Tannlege Lars Johan Gjestrum AS | Health & social care | 2017 |
| Tannlegene Eide & Steinsvoll AS | Health & social care | 2024 |
| Tannlegene I Sørbyen Da | Health & social care | 2006 |
| Taon Holding AS | | 2005 |
| Taurito Hotels AS | Real estate | 2016 |
| Taxi- Og Booking Service AS | Transport & logistics | 2022 |
| Tbinvest AS | | 2019 |
| Tcø Holding AS | Financial services | 2005 |
| Team Eiendom Gjøvik AS | Real estate | 2009 |
| Team Engineering AS | Professional & scientific | 2023 |
| Team Holding Gjøvik AS | Professional & scientific | 2023 |
| Team Media AS | Professional & scientific | 2024 |
| Team ST Transport Da | Transport & logistics | 1999 |
| Team Up Eiendom AS | Real estate | 2022 |
| Team Up Fellesskapspuls AS | Health & social care | 2024 |
| Team Up Holding AS | Health & social care | 2022 |
| Team-Up AS | Health & social care | 2022 |
| Techie Cloud Invest AS | | 2026 |
| Teknok AS | Administrative & support | 2020 |
| Tema Eiendom AS | Real estate | 1960 |
| Tema Næringsbygg AS | Real estate | 2007 |
| Tema Utvikling AS | Real estate | 2006 |
| Temp AS | Real estate | 2021 |
| Tenk Energi AS | Wholesale & retail | 2011 |
| Ter Eiendom AS | Real estate | 2022 |
| Ter Holding AS | Manufacturing | 2021 |
| Termografi Og Måleteknikk Gjøvik AS | Professional & scientific | 2006 |
| Tetentunet AS | Real estate | 2021 |
| Tewari Invest AS | Administrative & support | 2020 |
| Tge Holding AS | Real estate | 2007 |
| Thomasdalen 1 AS | Real estate | 2020 |
| Thomte Holding AS | Education | 2005 |
| Thrifty Holding AS | | 2020 |
| Tibau Invest AS | | 2020 |
| Tidløs Matglede AS | Hospitality | 2024 |
| TJ Agentur AS | Wholesale & retail | 2013 |
| Tjønnås Delikatesser AS | Wholesale & retail | 2022 |
| TK Autoteknikk AS | Other services | 2026 |
| TK Undervisning AS | Education | 2014 |
| TKK AS | Real estate | 2007 |
| TM Perilla AS | | 2021 |
| Tnek Holding AS | | 2026 |
| Toco Holding AS | Real estate | 2012 |
| Toini Christin Granum | Agriculture & fishing | 2013 |
| Tojmar AS | Wholesale & retail | 2012 |
| Tokerud Samtalepartner AS | Education | 2022 |
| Tokvam Invest AS | | 2005 |
| Tokvam Vekst AS | | 2026 |
| Tomtekompaniet AS | Real estate | 1999 |
| Tomter Og Stensrud Eiendom Ans | Real estate | 2004 |
| Tomtum Tak AS | Construction | 2018 |
| Tonga City AS | | 2024 |
| Tonga Eiendomsselskap AS | Real estate | 2016 |
| Topheim Holding AS | | 2026 |
| Topp Eiendom AS | Real estate | 2004 |
| Topro AS | Health & social care | 1966 |
| Topro Elektronikk AS | Manufacturing | 2017 |
| Topro Industri AS | Manufacturing | 2014 |
| Torbjørn Amundsen AS | Construction | 1980 |
| Torbjørn Fredlund Holding AS | | 2021 |
| Tordenskjoldsgate 3-5 Gjøvik AS | Real estate | 2007 |
| Tore Ruud Holding AS | | 2005 |
| Torggata 73 Hamar AS | Real estate | 2023 |
| Tork Holding AS | | 2026 |
| Torkehagen Invest AS | Construction | 1998 |
| Torm Holding AS | Real estate | 2005 |
| Tornado Handel AS | Wholesale & retail | 2023 |
| Tornado Holding AS | Wholesale & retail | 2005 |
| Torp-Ulstein Da | Information & communication | 2019 |
| Torshov Dagligvare AS | Real estate | 2017 |
| Toten Finans Og Forsikring AS | Financial services | 2012 |
| Toten Forsikring AS | Financial services | 2017 |
| Toten Vare-Express Neråsen & Neråsen Ans | Transport & logistics | 1988 |