| KiviCorp Oy | Administrative & support | 2022 |
| Kivikala kommandiittiyhtiö | Manufacturing | 2008 |
| Klassik service Oy | Other services | 2019 |
| Klassik-Trans Oy | Other services | 2015 |
| Knubes Software Oy | Information & communication | 2017 |
| Knuutila Konserni Oy | Financial services | 2026 |
| Kodeiksi Oy | Real estate | 2022 |
| Koirapalvelut J.Nyberg Oy | Other services | 2019 |
| KoivuCon Oy | Construction | 2024 |
| Kojarak Oy | Wholesale & retail | 2017 |
| KolCon Oy | Construction | 2001 |
| Kolisee Oy | Real estate | 2022 |
| Kolmen Sports Ky | Administrative & support | 1998 |
| Konditoria Talvio & Co | Manufacturing | 1992 |
| Koneistustyö Lehtelä Oy | Manufacturing | 1984 |
| Konepaja Santala Oy | Manufacturing | 1981 |
| Koneparkki Oy | Wholesale & retail | 2023 |
| Konepyörä R & R Oy | Wholesale & retail | 2006 |
| Konsulttitoimisto Tuloskonsultit Oy | Professional & scientific | 1982 |
| Koonti Oy | Transport & logistics | 2017 |
| Kooska Oy | Professional & scientific | 2014 |
| Kootar Oy | Wholesale & retail | 2016 |
| Kootatalot Oy | Construction | 2021 |
| Korjaamo AK-Saariset Oy | Other services | 2000 |
| Korjaamo ja Hitsaus Jari Järventausta Ky | Other services | 1994 |
| Koteja Lempäälä Oy | Professional & scientific | 2022 |
| Koti Valkonen Oy | Construction | 2014 |
| Kotilas Oy | Construction | 2018 |
| Kotitiellä Oy | Real estate | 2021 |
| Kotitiimi Hanna Oy | Health & social care | 2017 |
| Koto Spirits Oy | Manufacturing | 2022 |
| Kototuki Oy | Health & social care | 2019 |
| Koulutus Koukku Ky | Education | 2014 |
| Koulutus Oy Profus | Education | 2004 |
| Koulutus- ja kehityspalvelu Oy Jyrki A Inkeroinen | Professional & scientific | 2021 |
| Koy Hulikansarka | Real estate | 2023 |
| Koy Kirstaantie x | Real estate | 2025 |
| Koy Noutokatu 6 | Real estate | 2026 |
| Koy Petikko Parking | Real estate | 2026 |
| Koy Pietarsaaren Tehtaankatu 12 | Real estate | 2026 |
| Koy Pirkkala 6 | Real estate | 2026 |
| KraftPal Nordics Oy | Manufacturing | 2017 |
| Krike Group Oy | Construction | 2025 |
| Kuisman maa- ja metsätila Oy | Agriculture & fishing | 2025 |
| Kukkakauppa Kultamuratti Ky | Wholesale & retail | 2001 |
| Kuljetusliike E. Seppälä Oy | Transport & logistics | 1974 |
| Kuljetusliike Tyvi Oy | Transport & logistics | 1982 |
| Kuljun Rautarakenne Oy | Manufacturing | 1991 |
| Kuljun Verstas Oy | Education | 2024 |
| Kumo Corporation Oy | Financial services | 2024 |
| Kuningastalot Oy | Professional & scientific | 2012 |
| Kuparipenni Ky | Wholesale & retail | 2001 |
| Kura & Kauha Ky | Construction | 2001 |
| Kurki Invest Oy | Administrative & support | 2021 |
| Kuukki Oy | Other services | 2025 |
| Kuva Kompassi Oy | Professional & scientific | 2020 |
| Kuvaajana Oy | Information & communication | 1997 |
| Kuvauspalvelu Salopino Oy | Professional & scientific | 2022 |
| Kvalitatum Oy | Professional & scientific | 1988 |
| Ky Fincars Import Kg | Wholesale & retail | 2000 |
| Kylmäkosken Vuokrahallit Oy | Real estate | 1989 |
| Käpäläväki Oy | Wholesale & retail | 2018 |
| Kärki Farms Oy | Agriculture & fishing | 2024 |
| Kärkifix Oy | Construction | 2023 |
| Kärppälän Rustholli Oy | Hospitality | 2025 |
| Käsitellen Oy | Wholesale & retail | 2020 |
| Köse Solutions Oy | Financial services | 2025 |
| L & K Willman Oy | Transport & logistics | 2001 |
| LA Parturi-kampaamo Oy | Other services | 2025 |
| LA holding Oy | Financial services | 2021 |
| LAKKA Health Oy | Manufacturing | 2019 |
| LAKKA Technologies Oy | Manufacturing | 2016 |
| LC-Kaivin Oy | Construction | 1995 |
| LHR Group Oy | Construction | 2017 |
| LILAMI Oy | Professional & scientific | 2008 |
| LIN Invest Oy | Financial services | 2019 |
| LJJ-Company Oy | Hospitality | 2022 |
| LRK Center Oy | Agriculture & fishing | 2005 |
| LTV Profile Oy | Real estate | 2017 |
| LVI Lapland Oy | Construction | 2025 |
| LVI Nio Oy | Construction | 2011 |
| LVI Rakentava Oy | Construction | 2023 |
| LVI-Haapaniemi Oy | Construction | 2021 |
| LVI-Jämäkkä Oy | Construction | 2021 |
| LVI-Lipsonen Oy | Construction | 2004 |
| Labeat Oy | Professional & scientific | 2024 |
| LakeWave Technologies Oy | Information & communication | 2004 |
| Laki- ja yrityspalvelu Ratinen Oy | Professional & scientific | 2015 |
| Lakiasiaintoimisto Janne Ylijärvi Oy | Professional & scientific | 2010 |
| Lakikoti Oy | Other services | 2021 |
| Lammi Living Oy | Real estate | 2022 |
| Lammin Puutarhamulta avoin yhtiö | Agriculture & fishing | 2016 |
| Lappstudios Oy | Information & communication | 2025 |
| Larikka Automation Oy | Professional & scientific | 2018 |
| LasiHolli Oy | Construction | 1996 |
| Laskentamestarit Oy | Administrative & support | 2024 |
| Lastusten Kartano Oy | Agriculture & fishing | 2007 |
| Lauta Oy | Manufacturing | 1952 |
| LaxMat Invest Oy | Financial services | 2026 |
| Leanvention Oy | Information & communication | 2014 |