| Thomas Svendsen Holding AS | Charlottenlund | 2014 |
| Thomas Thoresen Tømmertransport AS | Årnes | 2012 |
| Thomas Tomaske Montageservice | De-14770 Brandenburg A.D. Havel | 2013 |
| Thomassen Anlegg AS | Alta | 2017 |
| Thomassen Bygg & Eiendom AS | Stavanger | 2024 |
| Thomassen Bygg & Maskin AS | Alta | 2017 |
| Thomassen Bygg AS | Sjøvegan | 2007 |
| Thomassen Bygg Og Eiendom AS | Tennevoll | 2014 |
| Thomassen Entreprenør AS | Staubø | 2000 |
| Thomassen Maskin AS | Alta | 2007 |
| Thomassen Rør AS | Lillesand | 2017 |
| Thomassen Traktor Og Maskin AS | Olderdalen | 2024 |
| Thomassen's Elektriske AS | Alta | 2023 |
| Thon & Co AS | Åmot | 1984 |
| Thon Bygg AS | Skiptvet | 2023 |
| Thon Bygg Og Teknik | Oslo | 2002 |
| Thon Maskin AS | Skrautvål | 2020 |
| Thor Capital AS | Trondheim | 2019 |
| Thor Dalan AS | Tomasjord | 2016 |
| Thor Enoksen AS | Røyken | 2002 |
| Thor Falkevik AS | Ålesund | 1981 |
| Thor Gjul AS | Opphaug | 2006 |
| Thor Hartvig Lunde AS | Tvedestrand | 2025 |
| Thor Inge Haltvik Bygg AS | Øystese | 2008 |
| Thor Jansen Malerfirma AS | Kokstad | 2012 |
| Thor Magne Hansen & Sønn AS | Lyngdal | 2003 |
| Thor Med Hammeren AS | Batnfjordsøra | 2025 |
| Thor Myrvang Gravefirma AS | Hønefoss | 1978 |
| Thor Norway Nuf | 14710 Villarrubia - Cordoba | 2016 |
| Thor Steinar Byggtjenester AS | Stavanger | 1998 |
| Thor Sverre Holding AS | Rissa | 2018 |
| THOR WIKE & Co AS | Hof | 1991 |
| Thoralf Myhre AS | Sandnes | 1977 |
| Thoralf Nilssen AS | Oppegård | 2022 |
| Thoralf Rognli AS | Bjarkøy | 2020 |
| Thorbjørn Helleberg AS | Vestre Gausdal | 2023 |
| Thorbjørn Odden AS | Skollenborg | 2024 |
| Thorbjørnsen Bygg AS | Mjøndalen | 2024 |
| Thore Knutsen Maskin Og Transport AS | Førresfjorden | 2007 |
| Thore Magnussen Og Sønn AS | Bøstad | 1995 |
| Thoreby Tak AS | Sarpsborg | 2019 |
| Thorell Group AS | Oslo | 2019 |
| Thorell Rør AS | Oslo | 2019 |
| Thorendahl AS | Oslo | 1991 |
| Thorendahl Holding AS | Oslo | 2019 |
| Thoresen Bygg AS | Kragerø | 2021 |
| Thoresen Invest AS | Oslo | 2005 |
| Thoresen Trapp Og Bygg AS | Rånåsfoss | 2024 |
| Thorgersen Maskin AS | Åmot | 2023 |
| Thori Marine Floors Rafal Sienkiewicz | Pl-83 111 Dabrowka Tczewska | 2023 |
| Thorkelsson Elektro AS | Vollen | 2018 |
| Thorleif Aas AS | Ørje | 1972 |
| Thorleif Rønning Transport AS | Vardø | 1996 |
| Thormodsen & Opheim Bygg Da | Haugesund | 2017 |
| Thormodsen Og Stølen Byggservice AS | Erdal | 2009 |
| Thormodsæter Entreprenør AS | Sæbøvik | 2009 |
| Thorn Baderom AS | Hundvåg | 2012 |
| Thorp Eiendom Og Anlegg AS | Ise | 2023 |
| Thorrud Prosjekt AS | Eidsfoss | 2005 |
| Thors Maskin AS | Halden | 2013 |
| Thorsen & Marcussen AS | Torød | 1987 |
| Thorsen & Pedersen Ans | Kristiansand S | 1987 |
| Thorsen Maskin AS | Kalandseidet | 2017 |
| Thorsen Maskin Og Fjellteknikk AS | Namsos | 2017 |
| Thorsen Montering AS | Fredrikstad | 2026 |
| Thorsen-Holding AS | Fredrikstad | 2021 |
| Thorshaug Rør AS | Frogner | 2023 |
| Thorsland Elektro AS | Åseral | 2018 |
| Thorsnes Bygg TB AS | Oslo | 2021 |
| Thorstein Lund Holding AS | Stavanger | 2018 |
| Thorstein Og Dag Konsulent AS | Kløfta | 1996 |
| Thorsteinsen Entreprenør AS | Blomsterdalen | 2015 |
| Thorstensen Eftf AS El Installatør | Tolvsrød | 1988 |
| Thorsås Grave Og Grunnarbeider AS | Hvittingfoss | 2018 |
| Thorvald Hansen AS | Fevik | 2010 |
| Thorvaldsen Entreprenør AS | Rud | 2007 |
| Thorød Betongarbeider AS | Stokke | 2011 |
| Thrios Bygg AS | Heimdal | 2024 |
| Thronæs-Takservice AS | Trondheim | 2024 |
| THT Kran Og Montasje AS | Kolbu | 2020 |
| Thu & Gursli Betong AS | Moi | 2006 |
| Thuen Bygg & Anlegg AS | Haugesund | 2025 |
| Thuen Bygg Holding AS | Haugesund | 2025 |
| Thuendalen AS | Hagavik | 2017 |
| Thule AS | Bønes | 2001 |
| Thunberg Betong AS | Larvik | 2025 |
| Thunberg Entreprenør AS | Larvik | 2014 |
| Thunder & Lightning Invest AS | Lillehammer | 2019 |
| Thunestvedt Elektriske AS | Grimstad | 1994 |
| Thunshelle & Ree AS | Nærbø | 2016 |
| THV AS | Eiken | 2011 |
| THV Holding AS | Espeland | 2013 |
| Thygesen AS | Aurskog | 1998 |
| Thygesen Total AS | Aurskog | 2022 |
| Thyholt Holding AS | Hell | 2005 |
| Thyssen Fahrtreppen GmbH | D-22096 Hamburg | 1997 |
| Thyssenkrupp Acessiabilidades Unip Lda | 8710 335 Sintra Lisboa | 2013 |
| Thømt Sikkerhet AS | Arendal | 2018 |
| Thøring & Aaheim AS | Lesjaskog | 2016 |
| Ti-To Eiendomsservice Da | Brattvåg | 1980 |