| SR Visual Oy | Information & communication | 2018 |
| Sabbagh Foods Oy | Wholesale & retail | 2025 |
| Sacode Oy | Information & communication | 2024 |
| Saigonese Oy | Hospitality | 2026 |
| Sakela Service Oy | Construction | 2024 |
| Sambaria Designs Oy | Manufacturing | 2019 |
| Sammutinpalvelu Saastamoinen Ky | Manufacturing | 1996 |
| Sanaset Oy | Health & social care | 2013 |
| Sanercon Oy | Construction | 2024 |
| Sannan Taksipalvelut Oy | Transport & logistics | 2025 |
| Sari ja Jukka Kivioja avoin yhtiö | Wholesale & retail | 2019 |
| Saunaniemen Kiinteistöt Oy | Real estate | 1997 |
| Scandinavian Berry Oy | Wholesale & retail | 2014 |
| Sector-One Oy | Wholesale & retail | 2008 |
| Selkopuu Ky | | 1982 |
| Sentinam Oy | Health & social care | 2017 |
| Seppo Trade Oy | Administrative & support | 1995 |
| Sepre Oy | Administrative & support | 2009 |
| Serien Oy | Construction | 2025 |
| Seripoint Oy | Manufacturing | 1990 |
| Servax Oy | Manufacturing | 2021 |
| Seven Stars Oy | Information & communication | 2022 |
| Shnoros Training Ky | Arts & recreation | 2012 |
| Shun Jia Yuan Oy | Hospitality | 2009 |
| Siivouspalvelu Taikasieni Ky | Administrative & support | 2009 |
| Siivouspalvelut Helena & Tytöt Avoin yhtiö | Administrative & support | 2008 |
| Sijoitusyhtiö Pentti Oy | Financial services | 2013 |
| Silkka Oy | Administrative & support | 2020 |
| Sillman Arkkitehtitoimisto Oy | Professional & scientific | 2005 |
| Sinokki Oy | Real estate | 2020 |
| Sirnikka Oy | Agriculture & fishing | 2003 |
| Sistory Oy | Real estate | 2017 |
| Skandi Oy | Construction | 2014 |
| Skillege Oy | Information & communication | 2010 |
| Smart Hotel Oy | Hospitality | 2020 |
| SoTeServices Minna Saastamoinen Oy | Health & social care | 2021 |
| Soitinmusari Ky | | 1981 |
| Soka Invest Oy | Financial services | 2022 |
| Solas Path Oy | Health & social care | 2026 |
| Solid Rock Oy | Manufacturing | 2021 |
| Sotkamon Hautaustoimisto Rusanen Oy | Other services | 2000 |
| Sotkamon Kaluste Ky Heino Pellikka Pauli Korhonen | | 1983 |
| Sotkamon Smer Avoin yhtiö | Hospitality | 1996 |
| SoulHealer Avoin Yhtiö | Arts & recreation | 2011 |
| Specialtrans Komulainen Ky | Transport & logistics | 2008 |
| Spicy Pizza Oy | Hospitality | 2020 |
| Sport Entertainment Facilities Finland Oy | Real estate | 2021 |
| Sporthero Oy | Arts & recreation | 2023 |
| Startify Oy | Manufacturing | 2016 |
| Streitti Joona Oy | Professional & scientific | 2021 |
| Strongway Oy | Financial services | 2020 |
| Studio Nemesis Oy | Other services | 2023 |
| Sumetku Oy | Agriculture & fishing | 2014 |
| Sunit Oy | Manufacturing | 1996 |
| Sunteekki Oy | Health & social care | 2017 |
| Suomen Finn-Kauppa Oy | Professional & scientific | 1994 |
| Suomen Komposiittitanko Oy | Professional & scientific | 2013 |
| Suomen Tilausmatkat Oy | Transport & logistics | 2018 |
| Super Imperium Oy | Other services | 2023 |
| Super M Oy | Professional & scientific | 2019 |
| Suunnittelu KAJO Oy | Professional & scientific | 2023 |
| Suunnittelu- ja Piirustuspalvelu A Heikkinen Oy | Professional & scientific | 2016 |
| Suunnittelu- ja Rakennuspalvelu Pääkkönen Oy | Professional & scientific | 1991 |
| Symbicon Oy | Professional & scientific | 2005 |
| Syvämiete Oy | Information & communication | 2017 |
| Sähköasennus M. Niemelä Oy | Construction | 1998 |
| Sähköasennus Moisanen Oy | Construction | 1997 |
| Sähkötoimisto Eltutek Oy | Construction | 2004 |
| Säräisniemen Kauppakartano Ky | | 1997 |
| T&J Sub Oy | Hospitality | 2009 |
| Timwood OY | Agriculture & fishing | 2020 |
| TJ-Center Oy | Wholesale & retail | 2003 |
| TJ-Hold Oy | Administrative & support | 2022 |
| TJR Games Oy | Information & communication | 2013 |
| TM Forest Oy | Agriculture & fishing | 1998 |
| Transport Ahy Limited, Suomen Sivuliike | Transport & logistics | 2017 |
| TROK Oy | Arts & recreation | 2018 |
| Takkarannan vesiosuuskunta | Construction | 2005 |
| Taksi E. Korhonen Ky | Transport & logistics | 2018 |
| Taksi Hentunen Oy | Transport & logistics | 2011 |
| Taksi Huotari Oy | Transport & logistics | 2012 |
| Taksi OoKoo Oy | Transport & logistics | 2023 |
| Taksi Sami Halonen Oy | Transport & logistics | 2015 |
| Taksikajana Oy | Transport & logistics | 2024 |
| Tandoori Koti Oy | Hospitality | 2026 |
| Tapio Albert Hämäläinen Oy | Administrative & support | 1999 |
| Tapiotek Oy | Information & communication | 2013 |
| Tarkastus Aki Oy | Professional & scientific | 2026 |
| Taxi Jani Partanen Oy | Transport & logistics | 2005 |
| Teeket Oy | Professional & scientific | 2026 |
| Teeri-Hevossuon jätevesiosuuskunta | Construction | 2014 |
| Tehi Parts Oy | Wholesale & retail | 2026 |
| Tehorempat Oy | Construction | 2023 |
| Telepoint Ky | Other services | 1977 |
| Teollisuustaito Oy | Professional & scientific | 2013 |
| Terhin Kotimaku Oy | Hospitality | 2012 |
| Teräsasennus Mankinen Oy | Manufacturing | 1991 |
| TevCode Oy | Information & communication | 2022 |
| Texact Oy | Manufacturing | 2026 |
| The Cozy Corner Oy | Hospitality | 2026 |