| Kommandiittiyhtiö Maansiirtopalvelu Keijo Savinainen | Wholesale & retail | 1974 |
| Kompass Commerce Oy | Professional & scientific | 2026 |
| Konditoria pH7 Oy | Wholesale & retail | 2007 |
| KoneKyyti Oy | Transport & logistics | 2025 |
| Konttoritar Oy | Administrative & support | 2025 |
| Korpilahti Oy | Financial services | 1987 |
| Korpipro Oy | Construction | 2025 |
| Kortelainen Yhtiöt Oy | Professional & scientific | 2023 |
| Kos Rakennus Oy | Construction | 2021 |
| Kosco Group Oy | Transport & logistics | 2011 |
| Kosco Invest Oy | Financial services | 2000 |
| Koskikara Invest Oy | Financial services | 2022 |
| Kotiin & Mökille Oy | Professional & scientific | 2023 |
| Kotipalvelu Eira Oy | Health & social care | 2026 |
| Koy Koskensillantien pysäköintilaitos | Real estate | 2025 |
| Kraano Oy | Wholesale & retail | 1993 |
| Krapihovi Oy | Hospitality | 2022 |
| Krapintila Oy | Professional & scientific | 2021 |
| Krisstal Oy | Other services | 2021 |
| Ks-kengitys oy | Agriculture & fishing | 2024 |
| Kuitukolmio Oy | Construction | 2026 |
| Kuitunen & Peltonen Ky | Hospitality | 1991 |
| Kuljetus J. Kiviranta Oy | Transport & logistics | 1994 |
| Kuljetus J. Laamanen Ky | Transport & logistics | 1987 |
| Kuljetus Kervinen Oy | Transport & logistics | 1999 |
| Kuljetus Oy Juha Laakso | Transport & logistics | 2004 |
| Kuljetus Oy Rautoja | Transport & logistics | 1980 |
| Kuljetus R. Stenvall Oy | Transport & logistics | 1976 |
| Kuljetus Suppala Oy | Transport & logistics | 1995 |
| Kuljetus Tasa Oy | Transport & logistics | 2013 |
| Kuljetus Teuvo Purmonen Oy | Transport & logistics | 1995 |
| Kuljetus Timo Mäkelä Oy | Transport & logistics | 2019 |
| Kuljetus Tuomo Väisänen Oy | Transport & logistics | 2018 |
| Kuljetus Vauhtikasi Oy | Transport & logistics | 1997 |
| Kuljetus Virranniemi Oy | Transport & logistics | 2017 |
| Kuljetus Wikholm Oy | Transport & logistics | 2013 |
| KuljetusDuunia Oy | Administrative & support | 2022 |
| Kuljetushuolto Oy | Transport & logistics | 1943 |
| Kuljetusliike A. Kulmala Oy | Transport & logistics | 1961 |
| Kuljetusliike A. Nordström Oy | Transport & logistics | 1987 |
| Kuljetusliike Eino Jokiniemi Oy | Transport & logistics | 1988 |
| Kuljetusliike H ja B Johansson Oy | Transport & logistics | 1990 |
| Kuljetusliike Köli Oy | Transport & logistics | 1961 |
| Kuljetuspalvelu E. Vaahermäki Oy | Transport & logistics | 1996 |
| Kuljetuspalvelu Teuvo Kujala Oy | Transport & logistics | 2006 |
| Kulmalan Pehtoori Oy | Agriculture & fishing | 2016 |
| Kultakuume Oy | Arts & recreation | 2006 |
| Kultalapio Oy | Financial services | 2021 |
| Kumino Oy | Wholesale & retail | 2017 |
| Kuninkaantien Rauta Oy | Wholesale & retail | 2006 |
| Kuopion Datalan Ky | Information & communication | 1990 |
| Kupari Kari Oy | Manufacturing | 2023 |
| Kupitas Oy | Professional & scientific | 2021 |
| Kurkoline Oy | Transport & logistics | 2021 |
| Kutomo-Holopainen Oy | Manufacturing | 2007 |
| Kuusipuu Consulting Oy | Professional & scientific | 2026 |
| Kuusisto-Kallioinen Oy | Financial services | 2020 |
| Kuvacode Oy | Information & communication | 2013 |
| Ky Ketunrauta Tuusula | Real estate | 1986 |
| Kylmä Nainen Oy | Arts & recreation | 2026 |
| Kylmäpumppu Oy | Manufacturing | 2024 |
| Kylmätieto Oy | Professional & scientific | 2022 |
| Kylpyhuone Kari Ky | Construction | 2004 |
| Käpylän Sähkö Oy | Construction | 1988 |
| L & L Tilintarkastus Oy | Professional & scientific | 1997 |
| L. Pinsel Oy | Construction | 2013 |
| LEVEL Autopalvelu Oy | Other services | 2025 |
| LKV Kranni Oy | Real estate | 2019 |
| LM Gustafsson Oy | Arts & recreation | 2021 |
| LMJ Rakennus Oy | Construction | 2019 |
| Loan & Hai Ky | Hospitality | 2008 |
| LT Grävtjänst AB | Construction | 2023 |
| LT-Kaivin Ky | Construction | 2002 |
| LVI FIXU Oy | Construction | 2021 |
| LVI Koponen Oy | Construction | 2018 |
| LVI Premium Oy | Construction | 2011 |
| LVI-Marjanen Oy | Construction | 1995 |
| LVI-Palvelu P. Hjelt Oy | Construction | 2009 |
| LVI-Prime Oy | Construction | 2021 |
| LVIS Putkisähkö Oy | Construction | 2026 |
| LaPi Oy | Professional & scientific | 2021 |
| Laatta- ja Kivirakenne Suorsa Oy | Construction | 2009 |
| Laatukaihdin Komulainen | Wholesale & retail | 2023 |
| Laatumallinnus Finland Oy | Professional & scientific | 2019 |
| Laitin Oy | Professional & scientific | 2023 |
| Lakiasiaintoimisto Oy Hujala Law | Professional & scientific | 2018 |
| Lammaskallion Audio Osk | Arts & recreation | 2017 |
| Lampi Invest Oy | Financial services | 2003 |
| Land Information Systems Oy | Hospitality | 1989 |
| Lapoon Rauhala Oy | Real estate | 1997 |
| Laricon Oy | Administrative & support | 2019 |
| Lassin laaturemontti Oy | Construction | 2025 |
| Lasten Terveyspalvelut Varimo Oy | Health & social care | 2023 |
| Lastenkirpputori Lilla Oy | Wholesale & retail | 2025 |
| Laten KH-Palvelut Oy | Administrative & support | 2015 |
| Laurient Oy | Administrative & support | 2016 |
| Lauttes Oy | Manufacturing | 2009 |
| Lavapojat Oy | Wholesale & retail | 2022 |
| Lavrenta Oy | Transport & logistics | 2022 |
| Layout Studio Oy | Professional & scientific | 1997 |