| Kotua Invest Oy | Financial services | 2019 |
| Kotua Oy | Construction | 2022 |
| KovatKivet LTD Corporation Oy | Real estate | 2024 |
| Koy Yrittäjäntie 4 | Real estate | 2023 |
| Kranor Elementtiasennus OY | Construction | 2019 |
| Kremi Rak Oy | Construction | 2018 |
| Kreos Oy | Construction | 2020 |
| Kriada Consulting Oy | Professional & scientific | 2026 |
| Kronos Capital Oy | Financial services | 2022 |
| Krymp Invest Oy | Financial services | 2010 |
| Kukka-Mökki Klaukkala Oy | Wholesale & retail | 2008 |
| Kuljetus Jokke J. Nyman Oy | Transport & logistics | 2002 |
| Kuljetus Peode Oy | Transport & logistics | 2017 |
| Kuljetus S. Mäkelä Oy | Transport & logistics | 2025 |
| Kuljetus Timo Åberg Oy | Transport & logistics | 1997 |
| Kuljetus-Soinisalo Oy | Transport & logistics | 1995 |
| Kuljetusliike Kimmo Anttila Oy | Transport & logistics | 2016 |
| Kuljetusliike Pentti A. Ahola Oy | Transport & logistics | 1971 |
| Kuljetusliike TuLi Linja Oy | Transport & logistics | 2011 |
| Kuljetusliike ja Logistiikka Heikki Aalto Oy | Transport & logistics | 2005 |
| Kuljetuspalvelu Tuukka Virtanen Oy | Transport & logistics | 2017 |
| Kuljetuspartio Oy | Transport & logistics | 2025 |
| Kullas Capital Oy | Financial services | 2021 |
| Kusari Capital Partners Oy | Real estate | 2026 |
| Ky Päämies | Other services | 1985 |
| Kylaheiko Consulting Oy | Administrative & support | 2013 |
| Kädestä Suuhun Oy | Professional & scientific | 2024 |
| L&H Verkkokaupat Oy | Wholesale & retail | 2018 |
| LH Holding Oy | Real estate | 2019 |
| LHA Rakennus Oy | Construction | 2021 |
| Linpo OY | Construction | 2002 |
| Listed LKV OY | Real estate | 2020 |
| LJ Career Oy | Administrative & support | 2018 |
| LK Tuotanto oy | Information & communication | 2024 |
| LK-Pakkaus Ky | Manufacturing | 1992 |
| LMEvents Oy | Administrative & support | 2019 |
| LMM-Kiinteistöt Oy | Other services | 2015 |
| LPS Performance Oy | Wholesale & retail | 2024 |
| LTE Holding Oy | Financial services | 1993 |
| LVI Caidon Oy | Construction | 2021 |
| LVI Pelkonen Oy | Construction | 2023 |
| LVI-DALTON GROUP Oy | Financial services | 2025 |
| Lvi-Dalton OY | Construction | 2006 |
| LVI-Konsultointi J. Pikki Oy | Professional & scientific | 1990 |
| LVI-Olenius Oy | Construction | 1993 |
| LVI-Palvelu Niku Oy | Construction | 2026 |
| LVI-Piste ML Oy | Construction | 2001 |
| LVI-toimisto Haapalainen Oy | Professional & scientific | 1989 |
| Laatoitus Klasila Oy | Construction | 2023 |
| Laatusiivous EP Oy | Construction | 2017 |
| Laatuteltta Vilkman Ky | Manufacturing | 1980 |
| Lahex Oy | Real estate | 1976 |
| Lahokoski Oy | Construction | 1999 |
| Lainajalat Oy | Health & social care | 2007 |
| Lakiasiaintoimisto Kari Oy | Professional & scientific | 1989 |
| Lakiasiaintoimisto Pulkkanen Oy | Professional & scientific | 2012 |
| Lakiasiantoimisto Seija Kärnä Oy | Professional & scientific | 1988 |
| Lakistonpuron Päiväkoti Oy | Education | 2019 |
| Lamminahon Arboristipalvelu oy | Agriculture & fishing | 2025 |
| Lampilan Kuljetus Oy | Transport & logistics | 2008 |
| Lande Race Oy | Arts & recreation | 2025 |
| Lanhaus Oy | Construction | 2004 |
| Lasilahti Invest Oy | Financial services | 2021 |
| Lasten kirppis Hattara Oy | Wholesale & retail | 2023 |
| Leaffield Oy | Financial services | 2024 |
| Lean Valmennus Oy | Professional & scientific | 2020 |
| Leditko oy | Construction | 2020 |
| Legentum Oy | Professional & scientific | 2008 |
| Leijona Lujitus Oy | Construction | 2016 |
| Leino Works Oy | Transport & logistics | 2020 |
| Leka Service Oy | Construction | 2018 |
| Lemmikkiliike Halikatti Oy | Wholesale & retail | 2026 |
| Lempihuone Oy | Professional & scientific | 2020 |
| Lepsämän Grillikioski Oy | Wholesale & retail | 2021 |
| Lerni Oy | Professional & scientific | 2015 |
| Letsfaceit Nordic Oy | Wholesale & retail | 2017 |
| Levyx Kiinteistöt Oy | Real estate | 2004 |
| Levyx Oy | Manufacturing | 2002 |
| Lex-Dialog Oy | Professional & scientific | 2013 |
| Lihi Oy | Other services | 2018 |
| Liikamaa Invest Oy | Financial services | 2022 |
| Liikuntakeskus Balanssi Oy | Real estate | 1989 |
| LindAs Oy | Real estate | 2021 |
| Lindeman Consulting Oy | Professional & scientific | 2007 |
| Lionline Oy | Administrative & support | 2022 |
| Lo-Rin Express Oy | Hospitality | 2024 |
| Lohjan Tilipalvelut Oy | Information & communication | 2022 |
| Lounaskahvila Kotoisa Oy | Hospitality | 2020 |
| Lumi Music Oy | Education | 2024 |
| Lux Sauna Oy | Wholesale & retail | 2022 |
| Luxury Production Oy | Professional & scientific | 2019 |
| Lyhtymies Oy | Arts & recreation | 2012 |
| Lykky Oy | Real estate | 1981 |
| M & M Henkilöstöpalvelu Oy | Construction | 2021 |
| M&T Hammarén Oy | Construction | 2010 |
| M-Crea Oy | Professional & scientific | 2009 |
| M-Experience Oy | Professional & scientific | 2023 |
| M. Meriläinen Oy | Construction | 2022 |
| M. Pellinen Oy | Wholesale & retail | 1989 |
| MAK-Kiinteistöt Oy | Real estate | 2007 |