| Kiinteistö Oy Kirkkonummen Einilä | Real estate | 1995 |
| Kiinteistö Oy Kirkkonummen Kotkankallio | Real estate | 1993 |
| Kiinteistö Oy Levin Eräloitsu | Real estate | 2000 |
| Kiinteistö Oy Loma-Anttila | Real estate | 1989 |
| Kiinteistö oy Saarnitie 2 | Real estate | 2024 |
| Kiinteistöhoito Nerola Oy | Administrative & support | 1989 |
| Kiinteistöosakeyhtiö Benestar | Real estate | 1989 |
| Kiinteistöosakeyhtiö Iniön Kesäkallio | Real estate | 1998 |
| Kiinteistöosakeyhtiö Seitahovi | Real estate | 1984 |
| Kiinteistötoimisto Hans Söderlund Oy | Real estate | 1984 |
| Kinhar Rakennus Oy | Construction | 2023 |
| Kinttuviisas Oy | Professional & scientific | 2016 |
| Kirjakas Ky | Real estate | 1991 |
| Knot Consulting Oy | Professional & scientific | 2026 |
| Kohdata Oy | Information & communication | 2022 |
| Kohonen & Partners Oy | Professional & scientific | 2020 |
| Koivisto Capital Oy | Financial services | 2015 |
| Koivisto Holding Oy | Financial services | 2017 |
| Kollegio Oy | Professional & scientific | 2026 |
| Kolmekahteen Oy | Professional & scientific | 2017 |
| Komia Menswear Oy | Wholesale & retail | 2018 |
| Kommanditbolag Wik-Invest Kommandiittiyhtiö Kjell Wikström | Real estate | 1972 |
| Konsulttitoimisto Aivoriihi Oy | Information & communication | 1982 |
| Koppsulting Oy | Professional & scientific | 2024 |
| Korsholmen Company Ab Oy | Professional & scientific | 2023 |
| Korsström & Korsström Oy | Professional & scientific | 2005 |
| Kuntokoulu Grani Hyvä Olo Oy | Arts & recreation | 2016 |
| Kuohuhouse Oy | Real estate | 2012 |
| Kupari Capital Oy | Financial services | 1990 |
| Kupari Group Oy | Financial services | 1997 |
| Kupari Solutions Oy | Information & communication | 1999 |
| Kvarkki Oy | Financial services | 1988 |
| L. Westerling Oy | Wholesale & retail | 1960 |
| LAW Invest Oy | Professional & scientific | 2019 |
| LJK-Yhtiö Oy | Real estate | 1983 |
| LOE Invest Oy | Real estate | 2013 |
| LOOP4 IT Services Oy | Professional & scientific | 2016 |
| LP Dental Oy | Health & social care | 2022 |
| LUN Group Oy | Real estate | 2023 |
| Laava Consulting Oy | Professional & scientific | 2020 |
| Ladugårdsgatan 9 Ab | Real estate | 2024 |
| Lagus Invest Oy | Financial services | 2024 |
| Lahjakoru Finland Oy | Wholesale & retail | 2020 |
| Lakiasiaintoimisto Jussi Karppinen Oy | Professional & scientific | 2012 |
| Lakiasiaintoimisto Ojajärvi - Verkkolaki Ky | Professional & scientific | 1997 |
| Lakirak Oy | Professional & scientific | 2008 |
| Laleko Oy | Financial services | 2026 |
| Larry Kiraffi Oy | Professional & scientific | 2024 |
| Lasati Oy | Professional & scientific | 1998 |
| Laudatur Holding Ab | Real estate | 2004 |
| Layer Zero Investments Oy | Financial services | 2021 |
| Leader Act Oy | Professional & scientific | 2017 |
| Lemmus Oy | Real estate | 2008 |
| Leskinen Training Oy | Other services | 2022 |
| Lettijeff Advisory AB | Professional & scientific | 2011 |
| Levanto Finland Oy | Manufacturing | 2026 |
| Levi Investment Partners Limited Oy | Real estate | 2026 |
| Levin Kitz Oy | Real estate | 2025 |
| Lexir Oy | Financial services | 2015 |
| LiabilityMan Oy | Financial services | 2026 |
| Lightlake Oy | Professional & scientific | 2002 |
| Liikkumatila Oy | Arts & recreation | 2021 |
| Lilia Eir Oy | Health & social care | 2025 |
| Lilleri Holding Oy | Financial services | 2023 |
| Lillinvest Oy | Financial services | 2007 |
| Lillis Holdings Oy Ab | Financial services | 2025 |
| Limmco Oy Ab | Professional & scientific | 2009 |
| Lind Prime Oy | Financial services | 2025 |
| Linjassa Oy | Professional & scientific | 2010 |
| Link Systems Oy | Professional & scientific | 1994 |
| Linnaea Borealis Oy | Financial services | 2019 |
| Linnalex Ab | Financial services | 2009 |
| Linnea Equities Oy | Financial services | 2016 |
| Little Creative Space Oy | Professional & scientific | 2021 |
| Live Levi Life oy | Hospitality | 2026 |
| Logger Sea Lines Oy | Transport & logistics | 1994 |
| Loiste Business Coaching and Consulting Oy | Professional & scientific | 2024 |
| Loket Partners Oy | Wholesale & retail | 2026 |
| Lotta-Sofia Visuals Oy | Professional & scientific | 2020 |
| Luotsi Yritysvastuupalvelut Oy | Professional & scientific | 2025 |
| Lussekatten Oy Ab | Professional & scientific | 2024 |
| Lyan Ab | Education | 2018 |
| Lynor Oy | Professional & scientific | 2026 |
| Lyx auto ja kuljetus Oy | Wholesale & retail | 2022 |
| Lähi-Optiikka Oy | Real estate | 1987 |
| Lähteelän Retkisatama Oy | Hospitality | 2025 |
| M & M Sähkö Ja Lämpö OY | Construction | 2016 |
| M & S Åstrand Oy | Wholesale & retail | 1996 |
| M Brewing Company Oy | Wholesale & retail | 2023 |
| M-Fly Oy | Professional & scientific | 2022 |
| MAIA Investments Oy | Financial services | 2014 |
| Male Industrial Solutions OY | Professional & scientific | 2002 |
| MCO Mobile Commerce Finland Oy | Real estate | 2000 |
| MHZolutions Ltd Oy | Professional & scientific | 2017 |
| MJS-Training Oy | Education | 1993 |
| MJY Capital Oy | Wholesale & retail | 2021 |
| MKG Finland Oy | Health & social care | 2017 |
| MKTH Investing Oy | Real estate | 2019 |
| ML Kiinteistö- ja Lakipalvelut Oy | Administrative & support | 2008 |
| MM Consulting Oy | Construction | 2023 |