| Seutusähkö Oy | Construction | 2020 |
| Siivous ja Kotiapu Irene Oy | Administrative & support | 2022 |
| Sis-Rak Oy | Construction | 1973 |
| Sivulause Oy | Arts & recreation | 2022 |
| Smelk Oy | Wholesale & retail | 1987 |
| Snowdog 2112 Oy | Financial services | 2026 |
| Soll Suomi Oy | Other services | 2022 |
| Sopurengas Kannisto Ky | Wholesale & retail | 1975 |
| Sosiaalipalvelu Laturi Oy | Health & social care | 2019 |
| Soveka Ky | Hospitality | 1992 |
| Sport Corner Oy | Wholesale & retail | 2008 |
| SuoRan Oy | Construction | 2020 |
| Suomen Hoitovirhejuristit Oy | Professional & scientific | 2025 |
| Suomen Kasviöljykierrätys Oy | Manufacturing | 1997 |
| Suomen Miljöörakennus Oy | Manufacturing | 1990 |
| Suomen Retkisauna Oy | Construction | 2021 |
| Suomen elatusjuristit Oy | Professional & scientific | 2023 |
| Suonpää Yhtiöt Oy | Wholesale & retail | 2012 |
| SynRex Oy | Professional & scientific | 2009 |
| Sähkö ja Kunnossapito Eskola Oy | Construction | 2013 |
| Sähkö-Suominen Oy | Construction | 2022 |
| Sähköasennus Marjamäki Oy | Construction | 1997 |
| Sähköinsinööritoimisto EKL-Suunnittelu Oy | Professional & scientific | 1989 |
| Sähköliike Hannu Rajala Oy | Construction | 2019 |
| Sähköurakointi TT Oy | Construction | 2009 |
| TEAMSERVU Avoin yhtiö | Information & communication | 2010 |
| TESD Investment Oy | Financial services | 2018 |
| THE Housing Oy | Construction | 2026 |
| TS Songs Oy | Information & communication | 2006 |
| TTH-Mechanics Oy | Wholesale & retail | 2025 |
| TTP-Ruusunen Oy | Construction | 1998 |
| Taksi Pentikäinen Oy | Transport & logistics | 2014 |
| Taksi Sundqvist Oy | Transport & logistics | 2015 |
| Taksi Wirtanen Oy | Transport & logistics | 2023 |
| Taksit Julkunen Oy | Transport & logistics | 2012 |
| Tammelin Asset Management Oy | Financial services | 2013 |
| Tarve Solutions Oy | Professional & scientific | 2025 |
| Telakka ja Teollisuuspalvelut Jarkko Ruusunen Ky | Construction | 1987 |
| Terano Oy | Households | 2019 |
| Tero Rovio Oy | Agriculture & fishing | 2018 |
| Teräs-Topi Oy | Manufacturing | 1983 |
| Textile Revolution Oy | Wholesale & retail | 2019 |
| Tiililinna Oy | Professional & scientific | 2019 |
| Tiimatuula Ky | Wholesale & retail | 1990 |
| Tikofarm Oy | Agriculture & fishing | 2025 |
| Tilipalvelu Katja Hakala Oy | Professional & scientific | 2001 |
| Tilipiste Minna Oy | Professional & scientific | 2026 |
| Tilitoimisto Aarnio Loimaa Oy | Professional & scientific | 1991 |
| Tilitoimisto Laaksonen Oy | Professional & scientific | 2024 |
| Timberwise Oy | Manufacturing | 1998 |
| Timo Koivula Oy | Wholesale & retail | 2004 |
| Toimi Works Oy | Manufacturing | 2025 |
| Toimitilat Harse Osakeyhtiö | Real estate | 2010 |
| Tupun Hyvinvointipalvelut Oy | Arts & recreation | 2010 |
| Turun Seudun Ambulanssipalvelu Oy | Health & social care | 1997 |
| Turun Seudun Kuljetus ja Nosto Oy | Transport & logistics | 2020 |
| Turvallisuuspaja Oy | Education | 2025 |
| Tuulensuun Palvelu Oy | Health & social care | 2004 |
| Tähtitupa Oy | Arts & recreation | 2026 |
| US Center Oy | Other services | 1999 |
| Umavek Ky | Manufacturing | 1989 |
| Urakointi Kai J.Jokinen Oy | Construction | 1997 |
| Urakointipalvelu Karén Oy | Mining & quarrying | 1978 |
| Uudenmaan Laatutalot Oy | Construction | 2018 |
| V-Twin City Oy | Wholesale & retail | 1996 |
| VIF-ww Oy | Manufacturing | 2022 |
| Valinta-Viks Oy | Wholesale & retail | 1973 |
| Vallox Oy | Manufacturing | 1987 |
| Varhia Oy | Professional & scientific | 2019 |
| VarmaTurva Oy | Health & social care | 2025 |
| Varsinais-Suomen Erikoispurku Oy | Water & waste | 2017 |
| Veli-Matti Pakkala Oy | Wholesale & retail | 2007 |
| Velj. Taberman Oy | Manufacturing | 1988 |
| Veljekset Peräaho Oy | Transport & logistics | 1996 |
| Velkuanmaan vesiosuuskunta | Water & waste | 2008 |
| Veloto Oy | Wholesale & retail | 1994 |
| Vengoing Oy | Administrative & support | 2026 |
| Verho-Tuomi, Kirsti Tuominen & Kumpp. | Wholesale & retail | 1978 |
| VictoryGym Oy | Arts & recreation | 2024 |
| Vidacon Oy | Professional & scientific | 2022 |
| Vihmax Oy | Construction | 2022 |
| Vinttiklinikka Oy | Professional & scientific | 2024 |
| Vuorisen Konepaja Oy | Manufacturing | 1979 |
| Vuorisen Liikenne Oy | Transport & logistics | 1998 |
| Välimäen Puutarha Oy | Agriculture & fishing | 1965 |
| WDT Asennus- ja hitsaustekniikka Oy | Manufacturing | 1996 |
| Waccons Oy | Professional & scientific | 2000 |
| Wallin Diesel Oy | Wholesale & retail | 2007 |
| Wanted TS Oy | Construction | 2005 |
| Warmix Oy | Wholesale & retail | 2023 |
| Wille Machines Oy | Manufacturing | 1968 |
| XL-Motor Oy | Manufacturing | 2005 |
| YPL Palvelu Oy | Professional & scientific | 1992 |
| Yes Realisointi Oy | Wholesale & retail | 2024 |
| Yritystarkastus Aki Nokso-Koivisto Oy | Professional & scientific | 1982 |
| Zakhouse Oy | Construction | 2001 |
| Zisters Avoin yhtiö | Wholesale & retail | 2009 |
| ai-onlinestore sf Oy | Wholesale & retail | 2024 |
| cansome oy | Information & communication | 2022 |
| eMesys Ky | Professional & scientific | 2003 |