| Kultasepänliike Aki Aro Oy | Wholesale & retail | 1984 |
| Kumara Oy | Wholesale & retail | 2001 |
| Kyrönjoen Metsätyö Oy | Agriculture & fishing | 2004 |
| Kyrönmaan Jätevesi Oy | Water & waste | 1985 |
| Kyrönmaan LVI Oy | Construction | 2012 |
| Kyrönmaan Markkinointi Oy | Wholesale & retail | 1987 |
| Käsityöliike AhkeraLiisa Oy | Wholesale & retail | 2018 |
| Kössinhalli Oy | Wholesale & retail | 1965 |
| Laihian Asennus OY | Manufacturing | 2008 |
| LM Green Holding Oy | Financial services | 2013 |
| Lai-Teräs Mäkinen Oy | Manufacturing | 1979 |
| Laihia Data Oy | Wholesale & retail | 1987 |
| Laihia Voimasali Oy | Arts & recreation | 2021 |
| Laihian Areena Oy | Real estate | 2011 |
| Laihian Autokoulu Oy | Education | 1981 |
| Laihian Autotarvike Oy | Wholesale & retail | 1996 |
| Laihian Hyötykiinteistöt Oy | Real estate | 2001 |
| Laihian Isoot Nuukat Oy | Arts & recreation | 2005 |
| Laihian Kuljetus Oy | Transport & logistics | 1974 |
| Laihian Laatupiha Ky | Administrative & support | 2017 |
| Laihian Laki Oy | Administrative & support | 2014 |
| Laihian Levypala Oy | Manufacturing | 2020 |
| Laihian Mallas Oy | Manufacturing | 1992 |
| Laihian Nuuka Lämpö Oy | Energy | 1998 |
| Laihian Osakehallit Oy | Real estate | 2015 |
| Laihian Rakennus Matti Viinamäki Ky | Construction | 1988 |
| Laihian Ravintolat Oy | Hospitality | 2017 |
| Laihian Sähkö Oy | Construction | 2022 |
| Laihian Tilapalvelu Oy | Administrative & support | 2023 |
| Laihian Tuote Oy | Manufacturing | 1976 |
| Laihian VSS-tilat Oy | Real estate | 2003 |
| Laihian Vakuutuspalvelu Oy | Financial services | 2011 |
| Laihian Yritystilat KOy | Real estate | 2025 |
| Laihian pizzeria ja ravintola Oy | Hospitality | 2022 |
| Laimet Oy | Manufacturing | 2025 |
| Laitech Oy | Construction | 2024 |
| Lakeuden Tili- ja Yrityspalvelut Ky | Professional & scientific | 1999 |
| Lemmetti Design Oy | Professional & scientific | 2018 |
| Lounas-kahvila Linjakas Oy | Hospitality | 2000 |
| Lyyskin Tila Oy | Agriculture & fishing | 2023 |
| Länsi-Lakeus Oy | Construction | 2024 |
| Länsityökalu Oy | Wholesale & retail | 2013 |
| Läntisentien Kiinteistöt Oy | Real estate | 2020 |
| Lääkäripalvelut Eija Finnilä-Laine Oy | Health & social care | 2023 |
| M Laulajan Autokorjaamo Oy | Other services | 2008 |
| MHM Solutions Ab Oy | Wholesale & retail | 2020 |
| Maatalousliike Puska Oy | Wholesale & retail | 1980 |
| Mansira Oy | Financial services | 1987 |
| Matrolight Oy | Wholesale & retail | 1980 |
| Metsäkoneyhtymä Antti ja Reino Tuori avoin yhtiö | Agriculture & fishing | 2017 |
| MiBuCo Oy | Professional & scientific | 2024 |
| Midicom Oy | Information & communication | 2013 |
| Midir Oy | Administrative & support | 2009 |
| Miettylän TSH Trans Oy | Transport & logistics | 1998 |
| Myllypieni Oy | Real estate | 2004 |
| Mäkelä Korporaatio Oy | Professional & scientific | 2023 |
| NM-Kodit Oy | Construction | 2022 |
| Nallen Remontti ja Rakennus Oy | Construction | 2011 |
| Nupelo Oy | Wholesale & retail | 2015 |
| OAJ Invest Oy | Financial services | 2022 |
| OUS-Kiinteistöt Oy | Real estate | 2009 |
| Okratec Oy | Real estate | 1993 |
| Omasijoitussiivet avoin yhtiö | Real estate | 2025 |
| OptiHold Oy | Financial services | 2017 |
| Optimal Motors Oy | Wholesale & retail | 2025 |
| Oravarohdos Oy | Wholesale & retail | 2022 |
| Ossano Scandinavia Oy Ab | Wholesale & retail | 1989 |
| Oy Cashbörs Ab | Financial services | 1986 |
| Oy FAIG-Trading Ltd | Wholesale & retail | 1988 |
| Oy Jujuco Ab | Construction | 2005 |
| Oy Logset Holding Ab | Real estate | 2000 |
| Oy Prestum Ab | Information & communication | 2001 |
| Oy Termec Service Ltd | Manufacturing | 1989 |
| PRO-Valut Oy | Manufacturing | 2021 |
| Paskana Oy | Arts & recreation | 2025 |
| Paukun Grilli- ja Pelikioski Oy | Hospitality | 2012 |
| Pentti Kananoja Oy | Professional & scientific | 1987 |
| Permito Oy | Financial services | 1989 |
| Person Invest Oy | Construction | 2020 |
| Petri Kamula Oy | Construction | 2002 |
| Pihlajamäki Group oy | Construction | 2025 |
| PoKa Consulting Oy | Professional & scientific | 2025 |
| Pohjanmaan Autoservice Oy | Other services | 2022 |
| Pohjanmaan Elämyspalvelu Avoin Yhtiö | Arts & recreation | 2008 |
| Pohjanmaan Hyötyjätekuljetus Oy | Water & waste | 1996 |
| Pohjanmaan Kaivuu ja Piikkaus Oy | Construction | 1990 |
| Pohjanmaan Kuorma-autokeskus Oy | Transport & logistics | 2003 |
| Pohjanmaan Mixon Oy | Construction | 1993 |
| Poronkankaan Vesi Oy | Water & waste | 1983 |
| Potinvest Oy | Financial services | 2025 |
| Powertrain Innovation Group Oy | Manufacturing | 2025 |
| Puisto Kortteeri Oy | Real estate | 2023 |
| Puukkoosaaren kaivin- ja kuljetus Oy | Construction | 1994 |
| Puukkoosaari Pryyveri Oy | Manufacturing | 2016 |
| Q-Tech Oy | Manufacturing | 2021 |
| RR Haketus Oy | Agriculture & fishing | 2024 |
| Raakateippi Oy | Professional & scientific | 2019 |
| Rahkakorpi Oy | Administrative & support | 2016 |
| RakennusPoola Oy | Administrative & support | 2017 |
| Rakennusliike Esko Poola Oy | Construction | 1995 |