| Kotila Trading Oy | Wholesale & retail | 2025 |
| Kourupalvelu Hölttä Oy | Wholesale & retail | 1980 |
| Kova - invest Oy | Agriculture & fishing | 2021 |
| Kuivasalmen vesiosuuskunta | Water & waste | 2003 |
| Kukka- ja elintarvikekioski Evi Mäki Ky | Wholesale & retail | 1990 |
| Kukkakauppa Seija Teittinen avoin yhtiö | Wholesale & retail | 1987 |
| Kukkamo Consulting Oy | Professional & scientific | 2024 |
| Kuljetus Arimet Oy | Transport & logistics | 2023 |
| Kuljetus Himanen Ky | Transport & logistics | 1995 |
| Kuljetus Jarmo Lampinen Oy | Transport & logistics | 2009 |
| Kuljetus Kaipainen Ky | Transport & logistics | 2011 |
| Kuljetus Kuosmala Oy | Transport & logistics | 2025 |
| Kuljetus Pulkkiset Ky | Transport & logistics | 2003 |
| Kuljetus Pöyry Oy | Transport & logistics | 2020 |
| Kuljetus Siiskonen Oy | Transport & logistics | 1998 |
| Kuljetus T Lampinen Ky | Transport & logistics | 2009 |
| Kuljetus Tahko Ky | Transport & logistics | 2001 |
| Kuljetus Tahvo Oy | Transport & logistics | 2016 |
| Kuljetusliike J ja R Laatikainen Ky | Transport & logistics | 1986 |
| Kuljetusliike Kanerva Oy | Transport & logistics | 2008 |
| Kuljetusliike Krivetz Oy | Transport & logistics | 1976 |
| Kuljetusliike Salli Oy | Transport & logistics | 2019 |
| Kuljetuspalvelu S & P Avikainen kommandiittiyhtiö | Transport & logistics | 1992 |
| Kuljetuspalvelut S. Liikanen Ky | Transport & logistics | 2010 |
| Kulmapirtti, Ky | Hospitality | 1980 |
| Kulta ja Kello Matiskainen Ky | Wholesale & retail | 1988 |
| Kuntatarkastajien Oy Clavis | Professional & scientific | 1993 |
| Kuopion Tavaratukku Oy | Wholesale & retail | 1993 |
| Kuoppala Co. Oy | Administrative & support | 2021 |
| Kupiter Oy | Manufacturing | 2024 |
| Kuplas Oy | Wholesale & retail | 2022 |
| Kutaisi Oy | Hospitality | 2025 |
| Kuusikallio Oy | Wholesale & retail | 2022 |
| KuvaMatti Ky | Professional & scientific | 2015 |
| Kyllölänsaaren Lomamökit Oy | Hospitality | 1988 |
| Kyyhkylä Oy | Health & social care | 2011 |
| Kyyhkylän Kartano Oy | Hospitality | 1998 |
| Käpykankaan käpy Oy | Professional & scientific | 2025 |
| Käyttötarvike Kontinen Ky | Manufacturing | 1989 |
| L. Martikainen Oy | Transport & logistics | 2015 |
| LJR-Holdings Oy | Wholesale & retail | 2009 |
| LMR Holdings Oy | Financial services | 2023 |
| LP-Palvelu Oy | Construction | 1989 |
| LVI Laitinen Oy | Construction | 2016 |
| LVI Rakennus ja Korjaus J Toivanen Ky | Construction | 1992 |
| LVI-Colvi Oy | Construction | 2020 |
| LVI-Insinööritoimisto U.Moisala Oy | Professional & scientific | 1989 |
| LVI-Mikkeli Oy | Construction | 2008 |
| LVI-asennus Haapalainen Oy | Construction | 2017 |
| LVI-asennus V. Räisä Oy | Construction | 1995 |
| La Sol Capital Oy | Financial services | 2022 |
| Laamanni Jukka Huiskonen Ky | Other services | 1979 |
| Laatikkopesu Halinen Oy | Administrative & support | 2002 |
| Laatutie Oy | Professional & scientific | 2009 |
| Lagopus lagopus Oy | Hospitality | 2020 |
| Laguna Oy | Other services | 2008 |
| Laitsaari Group Oy | Transport & logistics | 2026 |
| Laki ja Järjestys Oy | Professional & scientific | 2017 |
| Lakiasiaintoimisto Saimaa Oy | Professional & scientific | 2017 |
| Lakiasiaintoimisto Toukkari Ky | Professional & scientific | 2020 |
| Lakiasiaintoimisto varatuomari Petri Seppälä Oy | Professional & scientific | 1995 |
| Lakka Software Oy | Information & communication | 2021 |
| Landhaus Kartano Holding Oy | Real estate | 2022 |
| Landhaus Kekkola Oy | Hospitality | 2022 |
| Larmeko Oy | Agriculture & fishing | 1994 |
| Lasi-Saranki Oy | Construction | 1998 |
| Laskenta JKR Ky | Professional & scientific | 1985 |
| Laskenta M. Moilanen Oy | Professional & scientific | 2012 |
| Laskentamaa Oy | Professional & scientific | 2002 |
| Laskentaneliö Oy | Professional & scientific | 2006 |
| Laskentapilvi Ky | Construction | 2015 |
| Laskimo Palvelut Oy | Professional & scientific | 2006 |
| Launialan Elintarvikepuoti Oy | Wholesale & retail | 1991 |
| Launialan Kioski Oy | Wholesale & retail | 1990 |
| Launinvest Oy | Wholesale & retail | 1988 |
| Laura Jämsä Ky | Health & social care | 2012 |
| Laurikaisen Auto ja Vene Oy | Wholesale & retail | 2013 |
| LeMpi Spa Finland Oy | Manufacturing | 2018 |
| Leadsky Group Oy | Professional & scientific | 2020 |
| Leadsum Oy | Professional & scientific | 2023 |
| Legistor Oy | Financial services | 2025 |
| Leion Oy | Professional & scientific | 2008 |
| Leipomo Mikkeliläinen Ky | Manufacturing | 1981 |
| Leirin Pizza Oy | Hospitality | 2015 |
| Leivonmäen Lämpö Oy | Energy | 1995 |
| Lempeä Lämpö Oy | Energy | 1995 |
| Lepas Oy | Real estate | 2002 |
| Levera Oy | Professional & scientific | 2021 |
| Levin Joronjälki Oy | Real estate | 2007 |
| Lifestyleshop JH Oy | Wholesale & retail | 2022 |
| Lihantuottajat Oy | Administrative & support | 1973 |
| Lihavanpään vesiosuuskunta | Water & waste | 2003 |
| Liian Oy | Professional & scientific | 2021 |
| Liikennekoulu TopWay Oy | Education | 1976 |
| Linksal Oy | Financial services | 2025 |
| Linvas Oy | Wholesale & retail | 2020 |
| Lisesi Oy | Financial services | 1994 |
| Liukkonen Holding Oy | Real estate | 2020 |
| Lokakuljetus Harri Venäläinen Ky | Water & waste | 1991 |
| Lokoilu Oy | Education | 2022 |