| Tipaco Oy | Financial services | 2025 |
| Titani Turvapalvelut Oy | Administrative & support | 2025 |
| ToPeKo Oy | Administrative & support | 2020 |
| Toimistopalvelu Paju Oy | Professional & scientific | 1992 |
| Tomi T. Mattila Oy | Wholesale & retail | 2004 |
| Tomisys Oy | Information & communication | 2009 |
| Tonful Oy | Financial services | 2005 |
| Tony's Invest Oy | Financial services | 2006 |
| Torkkel Capital Management Oy | Real estate | 2025 |
| Torni Games Oy | Information & communication | 2019 |
| Tradentum Oy | Wholesale & retail | 2013 |
| Traditune Oy | Wholesale & retail | 1994 |
| TrueMind Oy | Health & social care | 2026 |
| Tuil Group Oy | Financial services | 2011 |
| Tuil Holding Oy | Financial services | 2022 |
| Tuloslaskelma Lapinlisä Oy | Professional & scientific | 2021 |
| Tupi Palvelut Oy | Other services | 2023 |
| Turf Gamechanger Oy | Administrative & support | 2017 |
| Tuu-Puu Oy | Wholesale & retail | 1987 |
| Tuusulanjärven Automyynti Oy | Wholesale & retail | 1993 |
| Twin Holdings Oy | Financial services | 2024 |
| Tyres Taxi Rent Oy | Administrative & support | 2014 |
| UTM House Oy | Construction | 2017 |
| UUKU Consulting Oy | Professional & scientific | 2018 |
| Unelmalemmikit Oy | Wholesale & retail | 2004 |
| Uniqer Oy | Health & social care | 2024 |
| Universal Technic Oy | Manufacturing | 2019 |
| Untamo Design Oy | Manufacturing | 2021 |
| Urakointi J. Hirvonen Oy | Transport & logistics | 2021 |
| Uudenmaan Kattohuolto Oy | Construction | 2012 |
| Uudenmaan Kolarikorjaamo Oy | Other services | 2013 |
| Uudenmaan Luxuslaatoitus Oy | Construction | 2008 |
| Uudenmaan Sisärakenne Oy | Construction | 2025 |
| Uudenmaan Talopalvelu Oy | Construction | 1990 |
| Uudenmaan Tehopesu Oy | Administrative & support | 2008 |
| V.A.M.I. Pre-loved Oy | Wholesale & retail | 2024 |
| VALOA hair Oy | Arts & recreation | 2003 |
| Vik OY | Wholesale & retail | 2002 |
| VLMedia Oy | Wholesale & retail | 1993 |
| VRU-Yhtiöt Oy | Professional & scientific | 1996 |
| VT-Fix Oy | Construction | 1996 |
| VW-Rak Oy | Construction | 2022 |
| Valo Capital Oy | Financial services | 2008 |
| Valopiiri Oy | Wholesale & retail | 1995 |
| Vartiokeskus Guard Center Oy | Administrative & support | 2000 |
| Veikkolan kartanon Talli Oy | Arts & recreation | 2023 |
| Veka-Mix Oy | Construction | 1993 |
| Veljekset Hirva Oy | Wholesale & retail | 2016 |
| Velkaraha Ventures Oy | Construction | 2026 |
| Velonix Oy | Transport & logistics | 2024 |
| Veluxe beauty studio Oy | Other services | 2022 |
| Verokonsultointi Järvenoja Oy | Professional & scientific | 1992 |
| Vesijohtoliike Silvander Oy | Construction | 2024 |
| Videman Outdoors Oy | Administrative & support | 2023 |
| Videman Renewal Oy | Professional & scientific | 2019 |
| Videoruutu Oy | Administrative & support | 1985 |
| Vihdin Autotalo Oy | Wholesale & retail | 1997 |
| Vihdin Betoni Oy | Manufacturing | 1999 |
| Vihdin Hautaustoimisto Kauhanen Ky | Other services | 1985 |
| Vihdin Hevostarvike Oy | Wholesale & retail | 2011 |
| Vihdin Hinauspalvelu R. Rosenqvist Oy | Transport & logistics | 2005 |
| Vihdin Jalkaterapia Ky | Health & social care | 1988 |
| Vihdin Juhlapalvelu, avoin yhtiö | Hospitality | 1989 |
| Vihdin Kalustetukku Oy | Wholesale & retail | 2013 |
| Vihdin Liikenne Oy | Administrative & support | 1977 |
| Vihdin Palvelut Oy | Other services | 2021 |
| Vihdin Pientalot Oy | Construction | 1992 |
| Vihdin Pinta-Fix Oy | Construction | 1990 |
| Vihdin Projektimestari Oy | Construction | 1998 |
| Vihdin Rakennustekniikka VRT Oy | Construction | 2002 |
| Vihdin Rakennusurakointi Oy | Construction | 2015 |
| Vihdin Sisärakennetekniikka Oy | Construction | 2011 |
| Vihdin Sosiaali- ja kuntoutusalan Tukikohta Oy | Health & social care | 2007 |
| Vihdin Suksela Oy | Agriculture & fishing | 1973 |
| Vihdin Toimitilat Oy | Real estate | 1966 |
| Vihdin Urheiluhallit Oy | Arts & recreation | 1989 |
| Vihdin kiinteistökanta Oy | Real estate | 2018 |
| Vihdin muutto ja varasto Oy | Transport & logistics | 2016 |
| Viherin Puu Oy | Manufacturing | 2018 |
| Vihreää valoa Oy | Information & communication | 2023 |
| Vihti-Data Oy | Wholesale & retail | 2013 |
| Villa PaSa Oy Rakennusten tarkastus- ja valvontapalvelut | Professional & scientific | 2025 |
| Vinsta Oy | Professional & scientific | 2026 |
| Virtaa Vanhuksille Oy | Education | 2024 |
| VisionVox Oy | Education | 2002 |
| Vito Logistics Oy | Professional & scientific | 2019 |
| Volttisähkö Oy | Construction | 1996 |
| WRX Company Oy | Information & communication | 2017 |
| Walmaco Oy | Professional & scientific | 1997 |
| Waterdance Investment Oy | Financial services | 2021 |
| WeFly Oy | Transport & logistics | 2017 |
| Webnocs Oy | Professional & scientific | 2015 |
| Wooden Group Oy | Administrative & support | 1998 |
| Wottenberger Holding Oy | Administrative & support | 2022 |
| X Company Oy | Professional & scientific | 2023 |
| YAK Oy | Hospitality | 2023 |
| YP-toiminnot Oy | Financial services | 2004 |
| Yhdenvertaisuusapu Oy | Professional & scientific | 2022 |
| Yritysapu Mirja Hartikainen Ky | Professional & scientific | 1987 |
| Yrttipirtti Oy | Wholesale & retail | 2016 |