| Rentikka Ky | Administrative & support | 2014 |
| Resultado Oy | Agriculture & fishing | 2025 |
| Retaw Arctic Oy | Manufacturing | 2018 |
| Rinta-Könnö Oy | Agriculture & fishing | 1976 |
| Rkoo Palvelut Oy | Real estate | 2021 |
| Ruokapalvelut Vaholuoto Oy | Hospitality | 2016 |
| S & Co Yhtiö Oy | Manufacturing | 1995 |
| S & O Service Oy | Construction | 2024 |
| S-H Enterprise Ky | Professional & scientific | 2009 |
| S. Mäkitalo Oy | Manufacturing | 1985 |
| SAT-Cars Oy | Wholesale & retail | 2021 |
| SIP-Viihde Oy | Wholesale & retail | 1999 |
| Sajura Oy | Professional & scientific | 2023 |
| Salomaa & Salomaa | | 1999 |
| SamSteel OY | Manufacturing | 2012 |
| Savannah avoin yhtiö | Arts & recreation | 1993 |
| Savunpoisto- ja turvajärjestelmät - SAPO - Oy | Manufacturing | 2006 |
| Seijan ja Sepon Lounastupa Oy | Hospitality | 2025 |
| Seppo Ryödi Oy | Construction | 1986 |
| Serix Special oy | Transport & logistics | 2018 |
| Siementila Suokas Oy | Agriculture & fishing | 2018 |
| Siksei Oy | Wholesale & retail | 2026 |
| Silepa Oy | Wholesale & retail | 1988 |
| Sinosaurus Oy | Financial services | 2016 |
| Sisustus- ja Lahjatavarain Erikoisliike Petriina Oy | Wholesale & retail | 1989 |
| Snap Consulting Oy | Professional & scientific | 2024 |
| Solarface Oy | Wholesale & retail | 2014 |
| Solarneva Oy | Energy | 2026 |
| Sontsa Oy | Real estate | 2025 |
| Sportsware Solutions Oy | Wholesale & retail | 2026 |
| Suit Networks Oy | Information & communication | 2008 |
| Suomen Laatuilma Oy | Administrative & support | 2007 |
| Suomen Osuuspankki, Andelsbanken Finland | Financial services | 1992 |
| Suomen Turvatuote Oy | Wholesale & retail | 2016 |
| Suotuuli Oy | Energy | 2014 |
| Suupohjan Akku ja Rengas Oy | Wholesale & retail | 1995 |
| Suupohjan Helmi Oy | Professional & scientific | 1995 |
| Suupohjan Huoltocenter Oy | Other services | 2013 |
| Suupohjan Kaivupalvelu Oy | Construction | 1994 |
| Suupohjan Kauppakeskus oy | Wholesale & retail | 1985 |
| Suupohjan Maataloustieto Ky | Professional & scientific | 2000 |
| Suupohjan Mittatupa Ky | Professional & scientific | 1988 |
| Suupohjan Seutupalvelukeskus Oy | Information & communication | 2001 |
| Suupohjan Seutuverkko Oy | Information & communication | 2005 |
| Suupohjan Sijoituspalvelut Oy | Real estate | 1979 |
| Suupohjan Sähkö RP Oy | Construction | 1990 |
| Suupohjan Talohuolto Oy | Administrative & support | 2019 |
| Suupohjan Tili-Isäntä Ky | Administrative & support | 1994 |
| Suupohjan Varaosa ja Huolto Oy | Wholesale & retail | 2001 |
| Sähkö Haavisto Oy | Construction | 2014 |
| Sähkö-Mäntylä Oy | Wholesale & retail | 2021 |
| Sähköpalvelu Saarenpää Ky | Construction | 1991 |
| Sähkötyö Kema Ky | Construction | 1992 |
| Säte Oy | Manufacturing | 2007 |
| TAIVU Technologies Oy | Information & communication | 2024 |
| Tci Laurila OY | Professional & scientific | 2009 |
| THE Group Oy | Financial services | 2021 |
| THT Paloneva Oy | Administrative & support | 1993 |
| TJ-Isännöinti Oy | Real estate | 2017 |
| TJ3 Audientis Oy | Professional & scientific | 1992 |
| TJK-Urakointi Oy | Construction | 2008 |
| TLZ Group Oy | Professional & scientific | 2014 |
| TOP-Pinnoitus Oy | Construction | 2019 |
| TP Trans Ky | Transport & logistics | 2004 |
| TSL Group Oy | Construction | 2020 |
| TT Automation Oy | Professional & scientific | 2026 |
| Taitoart Ky | Professional & scientific | 2005 |
| Taksi Tommi Salmenoksa Oy | Transport & logistics | 2013 |
| Talo- ja Kalustemira Oy | Wholesale & retail | 1986 |
| Tarveapuri Oy | Health & social care | 2025 |
| Taskilankuja Oy | Real estate | 1981 |
| Tavaratalo Uniikki Oy | Other services | 2022 |
| Teo Lehtimäki Oy | Professional & scientific | 1991 |
| Terotek Oy | Manufacturing | 2001 |
| Teuvan Kolarityöt Kommandiittiyhtiö, Erkki Mäkelä | Other services | 1976 |
| Think Pink Oy | Arts & recreation | 2021 |
| Tilakumppanit Oy | Real estate | 2023 |
| Tili-Center Nurmela Ky | Professional & scientific | 2002 |
| Tilintarkastus Kalliokoski Oy | Professional & scientific | 1987 |
| Tinax Oy | Wholesale & retail | 2016 |
| Toivemetsä Oy | Agriculture & fishing | 2021 |
| Toninox Oy | Manufacturing | 2020 |
| Topeekan Kaluste Oy | Wholesale & retail | 1991 |
| Topeekan Liikekiinteistöt Oy | Real estate | 2008 |
| Torppakahvila Soldat avoin yhtiö | Hospitality | 2000 |
| Traktoriurakointi Rotola-Pukkila Oy | Construction | 2011 |
| Tuisco Oy | Manufacturing | 2021 |
| Tuppu-Kaluste Oy | Wholesale & retail | 1985 |
| Turve Botnia Oy | Wholesale & retail | 1990 |
| Tyylitehtaat Ky | | 1976 |
| Työnohjaus- ja konsultointipalvelut Työniloa Oy | Professional & scientific | 2022 |
| Tähkälaakso Oy | Agriculture & fishing | 2018 |
| Tähtifysio Sari Varala Oy | Other services | 2012 |
| UK Majoitus Oy | Real estate | 2010 |
| Umut Baran Oy | Hospitality | 2019 |
| Urakoitsijakauppa Viertola Ky | Wholesale & retail | 1987 |
| Urpo Kuusniemi Ky | Arts & recreation | 1990 |
| Uusi Kasvu Osuuskunta (UKO) | Professional & scientific | 2017 |
| Uusi Kasvu Oy | Financial services | 2014 |
| Vakio-Sähkö Oy | Wholesale & retail | 2004 |