| Kuusela & Poika Oy | Transport & logistics | 1992 |
| Kuvaamo Into Oy | Professional & scientific | 2010 |
| Kuwax Oy | Professional & scientific | 2015 |
| Kyssä Management Oy | Professional & scientific | 2025 |
| Kähee Works Oy | Information & communication | 2017 |
| Käyttöilma Oy | Construction | 2019 |
| L&L Invest Oy | Financial services | 1995 |
| L&M Autopesu Oy | Other services | 2013 |
| LEKA-Hydro Oy | Real estate | 1990 |
| LEXIM Legal documents & advisory Oy | Professional & scientific | 2026 |
| LKK Energy Consulting Oy | Professional & scientific | 2024 |
| LOS-Toiminta Oy | Hospitality | 2024 |
| LSP Holding Oy | Financial services | 2026 |
| LV-Sähkö Oy | Construction | 2019 |
| LVI FeSET Oy | Construction | 2009 |
| LVI KotiLoimu Oy | Wholesale & retail | 2017 |
| LVI T. Kaapu Oy | Construction | 1996 |
| LVI-JoB Oy | Professional & scientific | 2021 |
| LVI-Lotikko Oy | Construction | 2018 |
| LVI-Pärnä Oy | Construction | 2026 |
| La Mel Oy | Hospitality | 2017 |
| Laattatyö Wikman Oy | Construction | 1997 |
| Laatukaivin Ojala Oy | Construction | 2012 |
| Laaturakennus Laine Oy | Construction | 2022 |
| Labsense Oy | Wholesale & retail | 2016 |
| Labtam Finland Oy | Information & communication | 1989 |
| Laiho Consultive Oy | Professional & scientific | 2024 |
| Lakeus Trading Oy | Wholesale & retail | 2021 |
| Lansas Trading Oy Ab | Wholesale & retail | 2001 |
| Lap Ark Oy | Construction | 2021 |
| Lapselle koti Oy | Health & social care | 2017 |
| Larieemeli Media Oy | Professional & scientific | 2021 |
| Lasitalo Oy Tampere | Construction | 2014 |
| Laskupiste Oy | Information & communication | 2018 |
| Latvalehti Oy | Hospitality | 2020 |
| Laudesepät Oy | Construction | 2015 |
| Laura Hytönen Oy | Wholesale & retail | 2023 |
| Laurila Business Group Oy | Professional & scientific | 2020 |
| Lehtiniemi Taisei Oy Ltd | Construction | 1998 |
| Leipomo Sorttiina Oy | Manufacturing | 2026 |
| Leipomo-Konditoria Kataja Oy | Manufacturing | 2003 |
| Lem PALA Oy | Financial services | 1977 |
| Leppäpellon Kotipuutarhat Oy | Agriculture & fishing | 2021 |
| LetsCap Oy | Financial services | 2016 |
| Lewaaw Media Oy | Information & communication | 2024 |
| LiVingArts Finland Oy | Arts & recreation | 2025 |
| Liedenpohjan Vesiosuuskunta | Water & waste | 1985 |
| Lifeturn Oy | Wholesale & retail | 2018 |
| Lighttalus Oy | Information & communication | 2021 |
| Liikemäärä Oy | Arts & recreation | 2024 |
| Liikenne Tiensuu Ky | Transport & logistics | 2010 |
| Liikkuva raha Oy | Professional & scientific | 2020 |
| Linvestment Oy | Financial services | 2017 |
| Listamies Oy | Wholesale & retail | 1990 |
| Liu Jiang Oy | Hospitality | 2019 |
| Location Art & Food Finland Oy | Information & communication | 2024 |
| Logistic Innovaatio Oy | Professional & scientific | 1992 |
| Loistepinta Oy | Construction | 2022 |
| Loisto Creative Oy | Professional & scientific | 2018 |
| Lokitek Oy | Construction | 2020 |
| Lotteri Oy | Professional & scientific | 2024 |
| Lounas - Kahvila Varjoska Oy | Hospitality | 2017 |
| Lu Fan Trade Avoin yhtiö | Hospitality | 2010 |
| Lumia Silfverberg Invest Oy | Financial services | 2024 |
| Lumoutuva Oy | Wholesale & retail | 2022 |
| Lvi Vimpan Putki Oy | Construction | 2022 |
| Lylytrading Oy | Real estate | 2005 |
| Lämpö kurko Oy | Construction | 2021 |
| LämpöPirkka Oy | Construction | 2021 |
| Länsi-Suomen Puunhankinta Oy | Agriculture & fishing | 2026 |
| Länsi-Suomen turva- ja hoivapalvelu Oy | Health & social care | 2021 |
| M Harhala Oy | Construction | 2015 |
| M Sähkö Oy | Construction | 2021 |
| M.P.A. Invest Oy | Wholesale & retail | 1989 |
| Makers Kauppa OY | Wholesale & retail | 2015 |
| MBrothers Oy | Real estate | 2025 |
| Mediavolyymi Osk | Professional & scientific | 2017 |
| Mge OY | Real estate | 2023 |
| MH-Metalli Heikkonen Ky | Manufacturing | 2005 |
| MJT Holding Oy | Information & communication | 2025 |
| MJV-Kiinteistöt Oy | Professional & scientific | 2008 |
| MK Purku Oy | Construction | 2020 |
| MMP-myynti oy | Construction | 2024 |
| MMTek Oy | Construction | 2008 |
| MPM Invest Oy | Financial services | 2021 |
| MR solutions Oy | Professional & scientific | 2020 |
| MR.putkimies Oy | Construction | 2014 |
| MT Ikkunat ja ovet Oy | Construction | 2023 |
| MV Betoni Oy | Manufacturing | 2010 |
| MV Betonilattiat Oy | Construction | 2021 |
| MV Terveys Oy | Health & social care | 2022 |
| MV parturi ja ink Oy | Other services | 2022 |
| MV-Lab Oy | Wholesale & retail | 1997 |
| Maalattu Oy | Wholesale & retail | 2023 |
| Maalaus- ja tasoitetyöt Kestilä Oy | Construction | 2017 |
| Maalauspalvelu Alén Oy | Construction | 2022 |
| Maanrakennus Eino Mäkinen kommandiittiyhtiö | Construction | 1975 |
| Maanrakennus Kivistö Oy | Construction | 2010 |
| Maanrakennus Mäkipala Oy | Construction | 1996 |
| Maanrakennus Yli-Marttila Oy | Construction | 2025 |