| Kurre IT & Software Oy | Information & communication | 2026 |
| Kustom Kulture Oy | Wholesale & retail | 2009 |
| Kuuhankalämpö Oy | Energy | 2013 |
| Kuuja Oy | Professional & scientific | 2020 |
| Kuuleva Oy | Health & social care | 2019 |
| Kuulokompassi Oy | Health & social care | 2025 |
| Kuuloxi Oy | Manufacturing | 2003 |
| Kuura Kodit Oy | Real estate | 2021 |
| Kuusan Lääkäripalvelu Oy | Health & social care | 2000 |
| Kuusi Kioski Oy | Hospitality | 2026 |
| Kuusjärven Raivaus Oy | Construction | 1964 |
| Kuutti Group Oy | Administrative & support | 2020 |
| Kuvistaa Oy | Wholesale & retail | 2025 |
| Kvanti Oy | Professional & scientific | 2024 |
| Kwork Innovaatiot Oy | Information & communication | 2014 |
| Kyllikki Clothing Oy | Wholesale & retail | 2021 |
| Kylmä- ja kodinkonehuolto J. Hokkanen Oy | Real estate | 1987 |
| Kylmä-Ässä Oy | Construction | 1988 |
| Kylmänoron Parkki Oy | Real estate | 2006 |
| Kyltix Oy | Manufacturing | 1992 |
| Kyläsuutari Jomaka Medi Ky | Wholesale & retail | 1995 |
| Kymppi Myynti Oy | Construction | 2019 |
| Kymppiremontit Group Oy | Professional & scientific | 2020 |
| Kymppiremontit Oy | Construction | 2009 |
| Kynsi-Vesi Invest Oy | Real estate | 1999 |
| Kynä ja Miekka Oy | Hospitality | 2004 |
| Kyytikuningas oy | Transport & logistics | 2021 |
| Käppi Ky | Wholesale & retail | 1964 |
| KärbäMed Oy | Health & social care | 2024 |
| Käsivarren Kämppä Oy | Real estate | 2014 |
| Kättelyllä Kuntoon Oy | Transport & logistics | 2025 |
| Köhniön kotiapu Oy | Administrative & support | 2017 |
| L-S Laatukala Oy | Agriculture & fishing | 1998 |
| L-salonki Oy | Other services | 2013 |
| L4R Invest Oy | Financial services | 2025 |
| LA Partner Oy | Real estate | 2021 |
| LC Technology OY | Information & communication | 2023 |
| Leevi's Taxi OY | Transport & logistics | 2025 |
| LH-Marketing Oy | Professional & scientific | 2018 |
| LKV Jyväskylänkiinteistöt Oy | Real estate | 2014 |
| LKV Savolin Oy | Real estate | 2001 |
| LKV Viitoset Ky | Real estate | 2010 |
| LL Team Oy | Health & social care | 2019 |
| LLG Invest Oy | Professional & scientific | 2019 |
| LLJ-Yhtiö Oy | Construction | 2015 |
| LMX Kiinteistöt Oy | Real estate | 2026 |
| LOAFALO Oy | Professional & scientific | 2019 |
| LOBAL Oy | Manufacturing | 2010 |
| LOULIE Beauty OY | Wholesale & retail | 2026 |
| LP Capital Oy | Real estate | 2025 |
| LP Scaffolding Oy | Administrative & support | 2022 |
| LS Cargo Logistics Oy | Transport & logistics | 2014 |
| LSA Consulting Oy | Professional & scientific | 2025 |
| LTJ Constructions Ky | Wholesale & retail | 1997 |
| LUNR Oy | Professional & scientific | 2026 |
| Luxtravel OY | Transport & logistics | 2022 |
| LVI Auvinen Oy | Construction | 2015 |
| LVI Huolto ja Asennus Juha Ranttila Oy | Construction | 2021 |
| LVI Kasamo Oy | Construction | 2007 |
| LVI Mak-Tek Oy | Construction | 2021 |
| LVI Suihkonen Oy | Construction | 2011 |
| LVI-Asennus Markku Satosaari Oy | Construction | 1992 |
| LVI-Gate Oy | Wholesale & retail | 2004 |
| LVI-Nero Oy | Construction | 2016 |
| LVI-Priimakodit Oy | Construction | 2011 |
| LVI-Suora Oy | Construction | 1981 |
| LVI-insinööritoimisto Koski-Konsultit Oy | Professional & scientific | 2018 |
| LVIS Talotekniset Oy | Construction | 2023 |
| La Belle kommandiittiyhtiö | Wholesale & retail | 1983 |
| LaFinesse Oy | Hospitality | 2021 |
| LaFonda Group Oy | Real estate | 2021 |
| LaKnu OY | Financial services | 2024 |
| Laadukkaat Neliöt Oy | Real estate | 2018 |
| Laajatalo Oy | Construction | 2022 |
| Laajis Oy | Arts & recreation | 2011 |
| Laanihippu Oy | Real estate | 2020 |
| Laanin Parkki Oy | Real estate | 2002 |
| Laatta Leevi Oy | Wholesale & retail | 1989 |
| Laattakymppi Oy | Construction | 2022 |
| Laatusiivous Auli Ky | Administrative & support | 2012 |
| Laatutrio Keski-Suomi Oy | Administrative & support | 2021 |
| Lacom Invest Oy | Administrative & support | 2021 |
| Lada Expert Oy | Wholesale & retail | 2024 |
| Lahden Autohuolto Oy | Other services | 2025 |
| Lainpelto Oy | Health & social care | 2026 |
| Laitehuolto Tevico Oy | Manufacturing | 2020 |
| Laituriosakeyhtiö Piikki Oy | Real estate | 2017 |
| Laituriosakeyhtiö Sauva Oy | Real estate | 2011 |
| Laive Oy | Education | 2017 |
| Lake Sauna Oy | Other services | 2021 |
| Lakeuden Autohuolto Oy | Other services | 2026 |
| Laki- ja veroasiaintoimisto Hokkanen Oy | Professional & scientific | 2025 |
| Lakiasiaintoimisto Equité Oy | Professional & scientific | 2020 |
| Lakiasiaintoimisto Fokus Oy | Professional & scientific | 2016 |
| Lakiasiaintoimisto Jarmo Suonpää Ky | Professional & scientific | 2005 |
| Lakiasiaintoimisto Martti Linnove Oy | Professional & scientific | 2008 |
| Lakiasiaintoimisto Olli Santanen Oy | Professional & scientific | 2022 |
| Lakiluotsit Oy | Professional & scientific | 1994 |
| Lakipalvelut Tuomo Loukiala Oy | Professional & scientific | 1993 |
| Lakkila Oy | Wholesale & retail | 1992 |