| Kotitukipalvelu ja Jalkahoito Lucky Feet Oy | Health & social care | 2023 |
| Kova ja Kiivas Oy | Hospitality | 2021 |
| Koy Raudoittajantie 14 | Real estate | 2022 |
| Kretuliini Oy | Professional & scientific | 2012 |
| Krouvi Näsi oy | Hospitality | 1996 |
| Krusberg Holding Oy | Financial services | 2026 |
| Krusberg Oy | Manufacturing | 2014 |
| Kuljetus Ek Oy | Transport & logistics | 2025 |
| Kuljetus J Kanerva Oy | Transport & logistics | 2022 |
| Kuljetus Jari Halmetoja Oy | Transport & logistics | 2007 |
| Kuljetus M. Holmström Oy Ab | Transport & logistics | 1990 |
| Kuljetus N. Timperi Oy | Transport & logistics | 2025 |
| Kuljetus P. Salin Oy Ab | Transport & logistics | 2022 |
| Kuljetusliike Aulis Selenius Oy | Transport & logistics | 1987 |
| Kuljetusliike B. Toivo Aaltonen & Kumpp. | Transport & logistics | 1961 |
| Kuljetusliike J Salomaa Oy | Transport & logistics | 1998 |
| Kuljetusliike Jorma Aaltonen Ky | Transport & logistics | 1990 |
| Kuljetuspalvelut Jari Rajala Oy | Transport & logistics | 2022 |
| Kultakuriiri Oy | Wholesale & retail | 2012 |
| Kultapalat Oy | Other services | 2019 |
| Kultasepänliike Aurum Ky | Wholesale & retail | 1981 |
| Kulttuurituotanto Päivi Rajakari Oy | Professional & scientific | 2008 |
| Kumina Music Oy | Arts & recreation | 1995 |
| Kumpa Oy | Hospitality | 2020 |
| Kumppanina Panganniemi Oy | Education | 1998 |
| Kumta Oy | Professional & scientific | 2017 |
| Kumula Oy | Financial services | 1968 |
| Kuninkaanportin Auto Oy | Wholesale & retail | 2025 |
| Kuninkaanportin tilat Oy | Real estate | 2025 |
| Kunnon Ukot Oy | Construction | 2024 |
| Kuntio Oy | Health & social care | 1992 |
| Kunto-Werner Oy | Arts & recreation | 2016 |
| Kuntokeskus Verde Oy | Arts & recreation | 2003 |
| Kuperkeikka Esikoulut Oy | Education | 1997 |
| Kuvabetoni Oy | Construction | 2022 |
| Kuvapulju Oy | Administrative & support | 2026 |
| Ky Entretek Kb | Other services | 2005 |
| Ky Lakiasiaintoimisto Kim Bergroth juridisk byrå Kb | Professional & scientific | 1993 |
| Ky Ole Öhman Kb | Wholesale & retail | 1981 |
| Ky Teemu Potkonen | Construction | 2009 |
| Ky Transmick Kb | Transport & logistics | 1980 |
| Kääriäinen Consulting Oy | Professional & scientific | 2024 |
| L-Tec Sport Oy | Wholesale & retail | 2009 |
| LA Lääkäripalvelut Oy | Health & social care | 2025 |
| Laamanaama OY | Hospitality | 2012 |
| Laatuase Finland OY | Wholesale & retail | 2007 |
| LC Viemärihuolto Oy | Water & waste | 2022 |
| LE-Kap Oy | Real estate | 2004 |
| LEKA-Invest Oy | Professional & scientific | 2017 |
| Lighthouse Capital OY | Financial services | 2007 |
| Liki Capital OY | Hospitality | 1998 |
| LJO Oy | Transport & logistics | 2021 |
| LKM-Konsultointi Oy | Professional & scientific | 1982 |
| LKV Tilat.fi Oy | Professional & scientific | 1991 |
| LM Silvennoinen Oy | Professional & scientific | 2022 |
| Local Traders Finland OY | Professional & scientific | 2010 |
| Loure OY | Wholesale & retail | 2011 |
| LR Putki Oy | Construction | 2023 |
| Luotsi Invest OY | Financial services | 2012 |
| LVI-Consulting Grönroos Oy | Professional & scientific | 1997 |
| LVI-Insinööritoimisto Wilén Oy | Professional & scientific | 2006 |
| LVI-MTek Oy | Construction | 2022 |
| Laagraf Oy | Real estate | 1953 |
| Laatoitus- ja rakennus Niemelä Oy | Construction | 2025 |
| Laatupalvelu TK Oy | Transport & logistics | 1994 |
| Lagomly Oy | Professional & scientific | 2023 |
| Lagus HorsePro Ky | Arts & recreation | 2009 |
| Lailulii Oy | Education | 2004 |
| Lakeuden Kiipeilykeskus Oy | Arts & recreation | 2026 |
| Lakiasiat Lex Justicia Oy | Professional & scientific | 2021 |
| Lamor Corporation Oyj | Wholesale & retail | 2006 |
| Lamor Recycling Oy | Water & waste | 2021 |
| Lamor Water Technology Oy | Water & waste | 2013 |
| Lamucon Oy | Administrative & support | 2018 |
| LandCon Oy | Construction | 2024 |
| Lankastudio Säie Wool Oy | Wholesale & retail | 2021 |
| Lappi Service Oy | Professional & scientific | 1993 |
| Larsen Family Corporation Oy | Real estate | 2003 |
| LasiYkköset Oy | Manufacturing | 2020 |
| Lasno Oy | Construction | 2013 |
| Lasse Paakkola Consulting Oy | Professional & scientific | 2023 |
| Lasse Wallden Oy | Wholesale & retail | 1990 |
| Latipac Oy Ab | Financial services | 2008 |
| Lattu Consulting Oy | Professional & scientific | 2020 |
| Lauri Laukkanen Oy | Information & communication | 2020 |
| Lavala Oy | Construction | 2025 |
| Lavalla Oy | Wholesale & retail | 2013 |
| Lavile Golf Oy | Wholesale & retail | 2021 |
| Lazypedro Oy | Wholesale & retail | 2010 |
| Le Petit Hédoniste Oy | Professional & scientific | 2022 |
| Le Vin Oy | Arts & recreation | 2021 |
| LeadGem Oy | Professional & scientific | 2023 |
| LeanOn Oy | Professional & scientific | 2025 |
| Lehtimäen Grilli Oy | Hospitality | 2016 |
| Leipomo-kahvila Mummon munkki Oy | Hospitality | 2018 |
| Lemonade Fashion Oy | Wholesale & retail | 1995 |
| Lempi Ventures Oy | Arts & recreation | 2020 |
| Lenmark Oy | Construction | 2024 |
| Leonard & Co Oy Ab | Hospitality | 2025 |
| Let Start Codingh Oy | Information & communication | 2025 |