| Laihon Romuliike Ky | Wholesale & retail | 1982 |
| Laimep Oy | Financial services | 2005 |
| Lainapuu Oy | Financial services | 2023 |
| Laine Yhtiöt Oy | Transport & logistics | 2007 |
| Lainto Engineering Oy | Wholesale & retail | 1998 |
| Laite-Consult Oy | Real estate | 1987 |
| Laitehuolto Helin Oy | Manufacturing | 2019 |
| Laiterä Consulting Oy | Professional & scientific | 2008 |
| Laitilan Huvilateollisuus Ky | Manufacturing | 1970 |
| Laivasisustus-Rusi Ky | Other services | 1981 |
| Laivasähkötyö Oy | Construction | 1977 |
| Laivurintallit Oy | Real estate | 2007 |
| Lakea Kiinteistökehitys Oy | Real estate | 2012 |
| Lakea Kiinteistöt 1 Ky | Financial services | 2020 |
| Lakea Rahastot Oy | Financial services | 2019 |
| Lakeus Control Oy | Administrative & support | 2024 |
| Laki ja Vesi Oy Turku | Professional & scientific | 2013 |
| Laki-Avekki Oy | Professional & scientific | 1990 |
| Lakiasiaintoimisto Agapeetus Oy | Other services | 2019 |
| Lakiasiaintoimisto Aldos Oy | Professional & scientific | 2016 |
| Lakiasiaintoimisto Antti Peltonen Oy | Professional & scientific | 2026 |
| Lakiasiaintoimisto Avola Oy | Professional & scientific | 1995 |
| Lakiasiaintoimisto Blackbird Oy | Professional & scientific | 2017 |
| Lakiasiaintoimisto Heikki Laiho Oy | Professional & scientific | 1988 |
| Lakiasiaintoimisto Heikkilä & Co HCO Oy | Professional & scientific | 2003 |
| Lakiasiaintoimisto Jenni Raiskio Oy | Professional & scientific | 2013 |
| Lakiasiaintoimisto Juha Paukkala, kommandiittiyhtiö | Professional & scientific | 2003 |
| Lakiasiaintoimisto Justico Oy | Professional & scientific | 1993 |
| Lakiasiaintoimisto Karhunen & Graff Oy | Professional & scientific | 2002 |
| Lakiasiaintoimisto Legimia Oy | Professional & scientific | 2017 |
| Lakiasiaintoimisto Makkonen Selander Similä Oy | Professional & scientific | 2024 |
| Lakiasiaintoimisto Meriluoto Oy | Professional & scientific | 2024 |
| Lakiasiaintoimisto Nina Karapuu Oy | Professional & scientific | 2020 |
| Lakiasiaintoimisto Pajula & Co Oy | Professional & scientific | 2016 |
| Lakiasiaintoimisto Pajula, Rosten & Lehmusvaara | Professional & scientific | 2016 |
| Lakiasiaintoimisto Palmgren Oy | Professional & scientific | 1990 |
| Lakiasiat Vehanen Oy | Professional & scientific | 1989 |
| Lakio Consulting Oy | Professional & scientific | 2025 |
| Lakipalvelu Signum Oy | Professional & scientific | 2013 |
| Lakir Oy | Hospitality | 2012 |
| Lakitoimisto Aarinen Oy | Professional & scientific | 2026 |
| Lakitoimisto Eero Kokkonen Oy | Professional & scientific | 2014 |
| Lakitoimisto Hannu Ylönen Oy | Professional & scientific | 1998 |
| Lakitoimisto Judicium Oy | Professional & scientific | 2001 |
| Lakitoimisto Kumpuvuori Oy | Professional & scientific | 2015 |
| Lakitoimisto LakiLähde Oy | Professional & scientific | 2025 |
| Lakitoimisto Lehtinen Sarainmaa & Viitanen Oy | Professional & scientific | 2022 |
| Lakitoimisto Suomi & Suvanto Oy | Professional & scientific | 2004 |
| LallTori Ky | Construction | 2013 |
| Laminex Oy | Real estate | 2010 |
| Lamiral Oy | Construction | 2026 |
| Lammer Trading Oy | Wholesale & retail | 1985 |
| Lammeta Oy | Information & communication | 2025 |
| Lammi Yhtiöt Oy | Manufacturing | 2026 |
| Lamminniemen Hyvinvointikeskus Oy | Health & social care | 2013 |
| Lanavent LVI.Oy | Construction | 2019 |
| LandBridge Oy | Professional & scientific | 2020 |
| Lander Oy | Real estate | 2022 |
| Langhus Oy | Real estate | 2013 |
| Lankonki Oy | Real estate | 2016 |
| Lapin Källä Oy | Hospitality | 2011 |
| Lapponia Kehitys Oy | Real estate | 1992 |
| Lapsen etu Oy Lakiasiaintoimisto | Professional & scientific | 1986 |
| Laptech Oy | Wholesale & retail | 2006 |
| Larex Oy | Professional & scientific | 2005 |
| Larimed Oy | Health & social care | 1997 |
| Larmik Oy | Information & communication | 2013 |
| Larscon Oy | Professional & scientific | 2004 |
| Larsen & Järvi Oy | Wholesale & retail | 2025 |
| Laru Invest Oy | Financial services | 2018 |
| Larus Quantum Oy | Information & communication | 2025 |
| Larypiercing Oy | Other services | 2020 |
| LaserPro Oy | Manufacturing | 2022 |
| Lasi-Kostamo Oy | Wholesale & retail | 1994 |
| Lasinpuhaltamo M. Hirvonen Oy | Manufacturing | 2003 |
| Lasitusliike Roininen Oy | Construction | 2008 |
| Laskentaidea Oy | Professional & scientific | 1997 |
| Laskentatieto Oy Irja Hirsinummi | Professional & scientific | 1981 |
| Lasku-Laite Oy | Wholesale & retail | 1974 |
| Lasku-Liite LL Ky | Professional & scientific | 2001 |
| LaskuAvain Oy | Administrative & support | 2023 |
| Laskuboxi oy | Information & communication | 2025 |
| Lassin Tunnit Ky | Education | 1991 |
| Last Gen Studios Oy | Information & communication | 2022 |
| Lastenlääkäripalvelut Lukkarinen Oy | Health & social care | 2011 |
| Lastenpäiväkoti Satunummi Oy | Education | 1974 |
| Lastensuojelupalvelut Kari Valikainen Oy | Health & social care | 2014 |
| Lastensuojelupalvelut Omppu Oy | Health & social care | 2015 |
| Lastentalo Mukulax Oy | Education | 2008 |
| Lastula Oy | Construction | 2022 |
| Lastunen Oy | Professional & scientific | 1989 |
| Late-Rakenteet Oy | Manufacturing | 1988 |
| Lateral Nord Oy | Information & communication | 2019 |
| Latija Oy | Construction | 2011 |
| Latinalainen Suukko Avoin Yhtiö | Arts & recreation | 2003 |
| Latua Turku Oy | Financial services | 2017 |
| Latva - Suurhallit Oy | Real estate | 1989 |
| Laukku Marjanen Ky | Wholesale & retail | 1990 |
| Laukku-Calabrese kommandiittiyhtiö, Marina Sysimetsä | Wholesale & retail | 1972 |
| Laukku-Rasti, avoin yhtiö | Wholesale & retail | 1989 |