| Kiinteistö Oy Putkikiinteistö | Real estate | 2004 |
| Kiinteistö Oy Sandön Kiltala | Real estate | 1987 |
| Kiinteistö Oy Työkuja 1 | Real estate | 2013 |
| Kiinteistö Oy Yrjönalho | Real estate | 2000 |
| Kingspan Oy | Wholesale & retail | 2011 |
| Kirjanpitotoimisto Da Capo Oy | Professional & scientific | 2011 |
| Kirjastomedia pmg Oy | Wholesale & retail | 1990 |
| Kirsikkaranta Oy | Hospitality | 2026 |
| Kjell's Kitchen Oy Ab | Hospitality | 2009 |
| Koda Capital Oy | Financial services | 2020 |
| Kodinrakentaja Oy | Construction | 2023 |
| Kolkan Kiinteistöpalvelu Oy | Administrative & support | 2022 |
| Konsulent SR Ky | Professional & scientific | 2023 |
| Konsultointi Kokkonen Oy | Professional & scientific | 1987 |
| Koskinen Sijoitus Oy | Real estate | 2000 |
| Kota Nord Oy | Education | 2020 |
| Kravto Oy | Transport & logistics | 2010 |
| KrisFix Oy | Construction | 2025 |
| KuivaTalo Oy Ab | Professional & scientific | 2019 |
| Kuljetus Jorma Winberg Ky | Transport & logistics | 2017 |
| Kuljetus ja Kaivuu Siivonen Oy Ab | Transport & logistics | 1987 |
| Kuura Pharma Oy | Wholesale & retail | 2023 |
| Kuusiston Putkityö Oy | Construction | 2012 |
| Kyrklund sanering saneeraus Ab | Construction | 2000 |
| L.N. Group Oy | Real estate | 1999 |
| LAVIS-Lavatanssijumppa Oy | Education | 2015 |
| LFE Invest Oy | Agriculture & fishing | 2013 |
| LJV Rakennus Ab Oy | Construction | 2026 |
| LM-Instruments Oy | Manufacturing | 1986 |
| LMaH Sijoitus Oy | Hospitality | 1983 |
| LQ Capital Ab | Real estate | 2025 |
| LT-Hydraulics Oy | Manufacturing | 1996 |
| LVI Halkosalmi Oy | Construction | 2019 |
| LVI-85 Oy | Construction | 2010 |
| LVI-Plumbing Oy | Construction | 2006 |
| LVI-Suunnittelu Janne Haapanen Oy | Professional & scientific | 2016 |
| LVI-asennus Mattila Oy | Construction | 2022 |
| Laboka aktiebolag | Professional & scientific | 1999 |
| Laco Language and Communication Care Oy | Education | 1995 |
| Lantbruksfastighet Ab Pellfols | Agriculture & fishing | 1998 |
| Larkkila Oy | Real estate | 1989 |
| Lasse Pernell Oy | Financial services | 1982 |
| Lehtinen & Ruohonen Oy | Administrative & support | 2000 |
| Leipomo Axo Oy | Wholesale & retail | 2023 |
| Lenke Oy | Construction | 2021 |
| Levee Oy | Manufacturing | 2022 |
| Lighthouse Entertainment Oy | Manufacturing | 1994 |
| Likosaari Oy | Real estate | 2019 |
| Lillmälö Båt Ab | Real estate | 1983 |
| Lindberg Properties Oy Ab | Real estate | 2012 |
| Linn Laulajainen Oy | Health & social care | 2024 |
| Linnanaukko Invest Oy | Financial services | 2014 |
| Liquid Zone Oy | Information & communication | 2006 |
| Litsa Consulting Oy | Professional & scientific | 2023 |
| Logmaster Invest Oy | Financial services | 2024 |
| LokalTapiola Sydkusten Ömsesidigt Försäkringsbolag | Financial services | 1936 |
| Lounais-Suomen Erä- ja Kalamatkat Oy | Administrative & support | 1999 |
| LundbergTrans Oy Ab | Transport & logistics | 2018 |
| Luode Consulting Oy | Professional & scientific | 2000 |
| MEF Holding Ab | Financial services | 2021 |
| MELANSHOPIT Avoin Yhtiö | Professional & scientific | 2017 |
| MK Marketmestarit oy | Wholesale & retail | 2017 |
| MLMH Holding Ab | Financial services | 2025 |
| MN-Plan Oy | Professional & scientific | 2024 |
| MNR-Projects Oy | Professional & scientific | 2024 |
| MPT Rakennus Oy | Construction | 2017 |
| MTY Invest Oy | Financial services | 2025 |
| Maanrakennus Wahe Ky | Construction | 2013 |
| Maatermia Oy | Construction | 2018 |
| Maija Arjasmaa Oy | Health & social care | 2011 |
| Majvik Gård Ab | Agriculture & fishing | 2019 |
| Malem Oy | Construction | 2014 |
| Marieta Oy | Hospitality | 2025 |
| Marina Pargas Ab | Transport & logistics | 2006 |
| Markkinointi Brunila Oy | Wholesale & retail | 1986 |
| Marvitek Oy | Professional & scientific | 2020 |
| Matmalmen Ab Oy | Administrative & support | 2003 |
| Matt-Cons Oy Ab | Construction | 2008 |
| Meaningless Productions Ab | Professional & scientific | 1996 |
| Melli Capital Oy | Financial services | 2023 |
| Menovehje Avoin yhtiö | Other services | 1982 |
| Meredin-Finland Oy | Transport & logistics | 1995 |
| Mikä-Art Oy | Wholesale & retail | 2019 |
| Milworks saneerauspalvelut Oy Ab | Construction | 2021 |
| Mingel Oy | Health & social care | 2019 |
| Mirhava Oy | Professional & scientific | 1994 |
| MixSan OY | Hospitality | 2023 |
| Modules Finland Oy | Manufacturing | 2009 |
| Mokeponi Ab | Professional & scientific | 2024 |
| Moodilia Oy | Wholesale & retail | 2014 |
| Muddaisten vesiosuuskunta | Water & waste | 2022 |
| Muurix Oy | Construction | 2007 |
| MvM Capital OY | Financial services | 2007 |
| Myötätuuli Oy | Professional & scientific | 1990 |
| Määrätieto Oy | Professional & scientific | 2009 |
| NJN-Tech Oy Ab | Wholesale & retail | 2005 |
| NK-East Oy | Financial services | 2005 |
| NK-Service Oy | Construction | 2024 |
| NKD Holding Oy | Financial services | 2006 |
| NS Consulting Ky | Professional & scientific | 1987 |