| Lainto & Geijer Investment Oy | Financial services | 2025 |
| Laitamaan vesiosuuskunta | Water & waste | 2005 |
| Laite.AI Oy | Information & communication | 2021 |
| Laitinen Advisors Oy | Professional & scientific | 2025 |
| Laitismaa Oy | Construction | 2024 |
| Laitoskone Oy | Administrative & support | 1974 |
| Laituri Zups Oy | Manufacturing | 2023 |
| Lake Family Trust Oy | Financial services | 2022 |
| Lake consulting Oy | Professional & scientific | 2022 |
| LakeHill Tactical Oy | Information & communication | 2024 |
| Lakeball Oy | Financial services | 2018 |
| Lakefront Oy | Financial services | 1997 |
| Lakegrove Oy | Financial services | 2023 |
| Lakeside Consulting Oy | Other services | 2024 |
| Lakeside Dental Oy | Health & social care | 2026 |
| Lakeside Group Oy | Professional & scientific | 2017 |
| Laki ja Yritys Kurkela Oy | Professional & scientific | 1978 |
| LakiCapital Oy | Professional & scientific | 1993 |
| LakiaTaloon Oy | Professional & scientific | 2024 |
| Lakianne Oy | Professional & scientific | 2025 |
| Lakiasiainpalvelut Rantasalo & Rantasalo Ky | Professional & scientific | 2005 |
| Lakiasiaintoimisto Adversus Oy | Professional & scientific | 2024 |
| Lakiasiaintoimisto Arto Palsala Oy | Professional & scientific | 1988 |
| Lakiasiaintoimisto Bergholm Oy | Professional & scientific | 1994 |
| Lakiasiaintoimisto Consilium Oy | Professional & scientific | 1999 |
| Lakiasiaintoimisto Ilmari Haapajoki Ky | Professional & scientific | 1985 |
| Lakiasiaintoimisto Jorma Turunen Oy | Professional & scientific | 1996 |
| Lakiasiaintoimisto Juristilinja Ky | Professional & scientific | 1991 |
| Lakiasiaintoimisto Juutilainen & Co Oy | Professional & scientific | 2006 |
| Lakiasiaintoimisto Kimmo Sarekoski Oy | Professional & scientific | 1997 |
| Lakiasiaintoimisto Laki ja Finanssi Ky | Professional & scientific | 1998 |
| Lakiasiaintoimisto LeXiMaX Oy | Professional & scientific | 2021 |
| Lakiasiaintoimisto Legato Oy | Professional & scientific | 2019 |
| Lakiasiaintoimisto Marina Nikula Ky | Professional & scientific | 2006 |
| Lakiasiaintoimisto Matti Kukko Oy | Professional & scientific | 2020 |
| Lakiasiaintoimisto Mykkänen Oy | Professional & scientific | 2021 |
| Lakiasiaintoimisto Nanipa Oy | Professional & scientific | 1994 |
| Lakiasiaintoimisto Nord Legal Oy | Professional & scientific | 2026 |
| Lakiasiaintoimisto Oiva Legal Oy | Professional & scientific | 2024 |
| Lakiasiaintoimisto Paasikallio Oy | Professional & scientific | 2010 |
| Lakiasiaintoimisto Pia Jääskeläinen Oy | Professional & scientific | 2023 |
| Lakiasiaintoimisto Varatuomari Heikki Meskanen Oy | Professional & scientific | 1995 |
| Lakihelppi Oy | Professional & scientific | 2022 |
| Lakily Oy | Professional & scientific | 2016 |
| Lakimiespalvelut Aavalex Oy | Professional & scientific | 2018 |
| Lakimiesten Valmiit Yhtiöt Oy | Professional & scientific | 1994 |
| Lakinavi Oy | Real estate | 2023 |
| Lakiston Ravintola Oy | Hospitality | 2019 |
| Lakitoimisto JSK Ky - Law Office JSK | Professional & scientific | 1992 |
| Lakitoimisto Koskikare Oy | Professional & scientific | 2023 |
| Lakitoimisto Oikeuden Sointu Oy | Professional & scientific | 2025 |
| Lakitoimisto Woima Partners Oy | Professional & scientific | 2026 |
| Lakkasuo Wind Farm Oy | Energy | 2022 |
| Laksri Oy | Hospitality | 2020 |
| Lalea Oy | Health & social care | 2001 |
| Lallemand Finland Oy | Manufacturing | 2013 |
| Lalu Consulting Oy | Health & social care | 2013 |
| Lalu Group Oy | Financial services | 2026 |
| Lambda Calculus Oy | Information & communication | 2021 |
| Lamek Finland Oy | Information & communication | 1998 |
| Laminaari Oy | Information & communication | 1979 |
| Lammala Konsult Ab Oy | Professional & scientific | 1990 |
| Lamminaho Palvelut Oy | Administrative & support | 2022 |
| Lamminnevan Tuulivoima Oy | Energy | 2021 |
| Lamminperänsuon Tuulivoimapuisto Oy | Energy | 2024 |
| Lampuset Oy | Real estate | 2012 |
| LandMan oy | Construction | 2019 |
| Landart Oy | Real estate | 1990 |
| Landecon oy | Construction | 2025 |
| Landsdorff Coaching & Consulting Oy Ab | Professional & scientific | 2022 |
| Landshark Oy | Financial services | 2020 |
| Lanfor Oy | Professional & scientific | 2016 |
| Langanpää Oy | Health & social care | 2021 |
| Langleben Technologies Oy | Information & communication | 2022 |
| Language Nomads Oy | Professional & scientific | 2025 |
| Langwitch Oy | Professional & scientific | 2004 |
| Langø Design Oy | Wholesale & retail | 1994 |
| Lankon Oy | Professional & scientific | 2013 |
| Lanne Capital Oy | Financial services | 2020 |
| Lanser Data Oy | Financial services | 1987 |
| Lantela Oy | Professional & scientific | 2021 |
| Lanttu Oy | Information & communication | 2023 |
| Lapa Oy | Construction | 1995 |
| Lape Consulting Oy | Health & social care | 2009 |
| Lapera Oy | Financial services | 2026 |
| Lapin Kelkkaparkki Oy | Real estate | 2020 |
| Lapin Kussa Oy | Real estate | 2026 |
| Lapin Vene ja Vaja Oy | Real estate | 1978 |
| Lapinkaira Yhtiöt Oy | Other services | 1988 |
| Lapinlahden Iso Petäjämäen Tuulivoima Oy | Energy | 2020 |
| Lapinlahti Data Center Oy | Information & communication | 2026 |
| Lapland Cosmetics Oy | Wholesale & retail | 2019 |
| Lapoet Consulting Oy | Wholesale & retail | 1978 |
| Lappnova Oy | Professional & scientific | 2025 |
| Laptime Finland Oy | Wholesale & retail | 2005 |
| Lara Invest Oy | Professional & scientific | 2019 |
| Larak Oy | Construction | 2017 |
| Larecom Oy | Professional & scientific | 2017 |
| Larnar Oy | Information & communication | 2020 |
| Laroscon Oy | Professional & scientific | 1993 |