| Safis Oy | Professional & scientific | 2019 |
| Sahi Trading House Oy | Wholesale & retail | 2016 |
| Saidok Oy | Professional & scientific | 2005 |
| Sairme Oy | Hospitality | 2024 |
| SajoCon Oy | Real estate | 2023 |
| Saken Sijoitus Oy | Manufacturing | 1992 |
| Sakiin Oy | Construction | 2008 |
| Sakses Oy | Professional & scientific | 2016 |
| Saku Capital Oy | Information & communication | 2026 |
| Salama sijoitus Oy | Real estate | 2022 |
| Saleoy Oy | Professional & scientific | 2024 |
| Sales Developers Special Ones Ky | Professional & scientific | 2015 |
| Saliter Oy | Hospitality | 2011 |
| Salmet Service Oy | Arts & recreation | 2026 |
| Salmisen Kioskit Oy | Real estate | 1992 |
| Salon Teknopaja Oy | Manufacturing | 2001 |
| Salty Dog Oy | Construction | 2013 |
| SamFinn Oy | Wholesale & retail | 2026 |
| SamOz Oy | Construction | 2020 |
| Samdem Oy | Other services | 2024 |
| Sampo-Rosenlew Oy | Manufacturing | 1989 |
| Sampolan Lämpö ja Huolto Oy | Administrative & support | 1975 |
| Sampolan Palvelukeskus Oy | Real estate | 1975 |
| Samuel Hilli Työnohjauspalvelut Oy | Health & social care | 2024 |
| Sanastin Oy | Financial services | 2025 |
| Sanbon Oy | Professional & scientific | 2006 |
| Sandy Beach Oy | Professional & scientific | 2016 |
| Saneerausmatti Ky | Construction | 1995 |
| Saneerauspalvelu Paltanen Ky | Construction | 2007 |
| SantaProfessional Oy | Arts & recreation | 2025 |
| Santala Invest Oy | Real estate | 2021 |
| Santas Break Company Oy | Administrative & support | 2024 |
| Saradua Oy | Other services | 2020 |
| Sas Se Production Oy | Real estate | 2004 |
| Sat-Cad Oy | Information & communication | 1993 |
| Sata Pinta Oy | Other services | 2003 |
| Sata Shipbuilding Oy | Manufacturing | 1989 |
| Sata Solutions Oy | Professional & scientific | 2012 |
| Sata-Hämeen Rakennuspalvelu Oy | Construction | 2017 |
| Sata-Hämeen Sijoitus Oy | Real estate | 2017 |
| Sata-Hämeen Viherrakennus Oy | Administrative & support | 2017 |
| Sata-Isännöinti, kommandiittiyhtiö | Real estate | 1990 |
| Sata-Kuulo Oy | Wholesale & retail | 1999 |
| Sata-Saneeraus Ky | Construction | 1982 |
| Sata-Tsamppala Oy | Agriculture & fishing | 1995 |
| SataControl Oy | Construction | 2015 |
| SataEasy Oy | Construction | 2010 |
| SataFox Oy | Manufacturing | 2013 |
| SataHUB Oy | Information & communication | 2025 |
| SataHuuto Oy | Wholesale & retail | 2023 |
| SataRescue Oy | Education | 2006 |
| SataValue Oy | Professional & scientific | 2024 |
| SataX-palvelut Oy | Administrative & support | 2002 |
| Satabusiness Oy | Financial services | 1989 |
| Satadetail Oy | Construction | 2026 |
| Satafriko Oy | Manufacturing | 2011 |
| Satahämeen Lava Ky | Water & waste | 1992 |
| Satakunnan Aluetaksi Oy | Transport & logistics | 1993 |
| Satakunnan Asuntovuokraus Oy | Real estate | 1994 |
| Satakunnan Atk-Tuote Oy | Wholesale & retail | 1987 |
| Satakunnan Autohuolto Oy | Other services | 2025 |
| Satakunnan Autopelti Ky | Other services | 2011 |
| Satakunnan Autopinta Oy | Other services | 2010 |
| Satakunnan Eläinlääkäriasema Oy | Professional & scientific | 1989 |
| Satakunnan Garden Oy Ab | Agriculture & fishing | 2026 |
| Satakunnan Hansa Oy | Hospitality | 1991 |
| Satakunnan Hautaustoimisto Oy | Other services | 2005 |
| Satakunnan Kaivuu- ja Työpalvelu Ky | Construction | 1992 |
| Satakunnan Karhukiinteistöt Oy | Real estate | 2012 |
| Satakunnan Kestosuojaamo Ky | Other services | 1966 |
| Satakunnan Kivipalvelu Ky | Manufacturing | 1987 |
| Satakunnan Laatuauto Oy | Wholesale & retail | 2021 |
| Satakunnan Lakaisijat Oy | Professional & scientific | 2020 |
| Satakunnan Linjatekniikka Ky | Construction | 2016 |
| Satakunnan Lämpöasennus Oy | Construction | 2022 |
| Satakunnan Löytötavaratoimisto Kommandiittiyhtiö | Administrative & support | 2010 |
| Satakunnan M-Rakennustoimisto Oy | Professional & scientific | 1999 |
| Satakunnan Marttapalvelut Oy | Administrative & support | 2009 |
| Satakunnan Me-Ra Technical Service Oy | Manufacturing | 1995 |
| Satakunnan Messut Oy | Administrative & support | 1995 |
| Satakunnan Metsäpalvelut ky | Agriculture & fishing | 2005 |
| Satakunnan Monimerkki Korjaamo Oy | Other services | 2014 |
| Satakunnan Muutto- ja Lähettipalvelu avoin yhtiö | Other services | 2001 |
| Satakunnan Neurologipalvelu Oy | Health & social care | 1994 |
| Satakunnan Näkökeskus Oy | Wholesale & retail | 2010 |
| Satakunnan Orto-dent Oy | Health & social care | 1998 |
| Satakunnan Osuuskauppa | Wholesale & retail | 1917 |
| Satakunnan Rakennekuivaus Oy | Construction | 2005 |
| Satakunnan Rakennustekniikka Ky | Construction | 2012 |
| Satakunnan Safetycontrol Ky | Public administration | 1996 |
| Satakunnan Sammutinhuolto Oy | Manufacturing | 1992 |
| Satakunnan Senioripalvelu Pori Ky | Health & social care | 2015 |
| Satakunnan Silmä ja Korva oy | Health & social care | 2004 |
| Satakunnan Suunnittelu ja Saneeraus Ky | Construction | 1999 |
| Satakunnan Sähkösuunnittelu Oy | Professional & scientific | 2023 |
| Satakunnan TAKUUPALVELUT OY | Health & social care | 2014 |
| Satakunnan Taide- ja Kehysliike Pinokkio Oy | Professional & scientific | 1992 |
| Satakunnan Talopalvelu Ky | Administrative & support | 1983 |
| Satakunnan Taloteknikot Oy | Construction | 2020 |
| Satakunnan Teknologiapalvelu Oy | Administrative & support | 2013 |