| Koy Kokkolan Kotimaja | Real estate | 2002 |
| Kra tip khao Thai cuisine Oy | Hospitality | 2022 |
| Krono-Trans Oy | Transport & logistics | 2008 |
| Kuivauspalvelu KSK Oy | Construction | 1991 |
| Kujanturkis Oy | Agriculture & fishing | 1979 |
| Kuljetus Ari Joutsi Ky | Transport & logistics | 2001 |
| Kuljetus E ja I Herronen Oy | Transport & logistics | 1995 |
| Kuljetus Harju Oy | Transport & logistics | 1994 |
| Kuljetus J. Koskinen Oy | Transport & logistics | 2025 |
| Kuljetus N.Niemi Oy | Transport & logistics | 2023 |
| Kuljetus Noponen Oy | Transport & logistics | 2019 |
| Kuljetus Penttilä Oy | Transport & logistics | 2011 |
| Kuljetus Puutio Oy | Transport & logistics | 2020 |
| Kuljetus Ronkainen Oy | Transport & logistics | 2006 |
| Kuljetus S.Luokkala Oy | Transport & logistics | 2009 |
| Kuljetusliike Harri Tuominen Oy | Transport & logistics | 1992 |
| Kuljetusliike Jorma ja Hannu Roiko Ky | Transport & logistics | 1980 |
| Kuljetusliike Lindgren Oy | Transport & logistics | 1975 |
| Kuljetusliike R. Lindell Oy | Transport & logistics | 1998 |
| Kuljetusliike Thoden Oy | Transport & logistics | 1993 |
| Kuljetusliike Vähärautio kommandiittiyhtiö | Information & communication | 1981 |
| Kuljetuspalvelu M. Kiviniemi Oy | Transport & logistics | 2009 |
| Kuljetuspalvelu Mikko Lunki Oy | Transport & logistics | 2022 |
| Kulmakaappi Oy | Wholesale & retail | 1978 |
| Kultasepänliike Hanna Niemi Oy | Wholesale & retail | 2012 |
| Kultasepänverstas Laura Nissi Oy | Manufacturing | 2020 |
| Kunnari Holding Oy | Real estate | 2021 |
| Kuntohelppi Oy | Arts & recreation | 2020 |
| Kupilan Autokoulu Oy | Education | 1980 |
| Kupira Oy | Manufacturing | 2016 |
| Kuri Technologies Oy | Manufacturing | 2021 |
| Kurikkalan Kaiverrus Oy | Manufacturing | 2023 |
| Kurjuuden pojat Oy | Arts & recreation | 2024 |
| Kustannusosuuskunta Länsirannikko - Förlagsandelslag Västkusten | Information & communication | 1990 |
| Kuulas Holding Oy | Financial services | 2022 |
| Kuulumo Ky | Education | 2022 |
| Kvikantin Hoiva Oy | Health & social care | 2018 |
| Kvikantin Ratsutila Oy | Arts & recreation | 2005 |
| Ky AK-Speed Kb | Wholesale & retail | 1999 |
| Ky Benotti Kb | Wholesale & retail | 1991 |
| Ky Kålan Höyrysaha - Kåla Ångsåg Kb. | Manufacturing | 1969 |
| Ky Rakennustoimisto K.I. Nilsson Byggnadsbyrå Kb | Construction | 1967 |
| Kynkään kettutarha avoin yhtiö | Agriculture & fishing | 1975 |
| Källströms Persienn Ab - Källströmin Kaihdin Oy | Manufacturing | 1949 |
| Kälviän HVV-Kiinteistöt Oy | Real estate | 2015 |
| Kärry Center Group Oy | Real estate | 2026 |
| Käsitys Oy | Professional & scientific | 2015 |
| Käsityöpuoti Lily Oy | Wholesale & retail | 2024 |
| Kölimiehet Oy | Manufacturing | 2019 |
| L&H Works oy | Construction | 2022 |
| L-Soft Marjaana Oy | Information & communication | 1996 |
| LC Partners OY | Professional & scientific | 2005 |
| LCC Group Oy | Professional & scientific | 2023 |
| LCP Industry Oy | Manufacturing | 2006 |
| LCP Kokkola Oy | Professional & scientific | 2006 |
| LCP Sijoitus Oy | Financial services | 2026 |
| Leipomo Emilie OY | Manufacturing | 2011 |
| LK's Beauty Oy | Other services | 2023 |
| LKV Pohjanmaan Kodit Oy | Real estate | 2025 |
| LMT Official avoin yhtiö | Professional & scientific | 2024 |
| LOGIS Finland Oy | Transport & logistics | 2026 |
| LR Urakointi OY | Construction | 2021 |
| LV Partners Oy | Wholesale & retail | 2025 |
| LVI - suunnittelu Pauli Unkuri Ky | Professional & scientific | 1989 |
| LVI Hosionaho Oy | Construction | 2012 |
| LVI Komanse Oy | Construction | 2019 |
| LVI Lapinoja Oy | Construction | 2022 |
| LVI Mankinen Oy | Construction | 2024 |
| LVI-Kokko Oy | Construction | 2015 |
| LVI-Rahkola Oy | Construction | 2020 |
| LVI-Service M.Lensu Oy | Construction | 2014 |
| LVI-Työt Kakkuri Oy | Construction | 2009 |
| LVT ravintolat Oy | Hospitality | 2026 |
| La Glace Oy Ab | Hospitality | 2024 |
| LaasOne Oy | Information & communication | 2017 |
| Lacar Oy | Wholesale & retail | 2025 |
| Lagom4U Oy | Financial services | 2018 |
| LaiRak Oy | Construction | 2017 |
| Laikko Consulting Oy | Professional & scientific | 2022 |
| Lake Resort Paljakka Oy | Real estate | 2021 |
| Lakiasiaintoimisto Janne Forss Oy | Professional & scientific | 2018 |
| Lakiasiaintoimisto Krook Ky | Professional & scientific | 2002 |
| Lakiasiaintoimisto Toni Kuosmanen Oy | Professional & scientific | 2020 |
| Lamesa Oy | Construction | 2012 |
| Lammassaaren Viemäriosuuskunta | Water & waste | 2010 |
| Lampela Invest Oy | Real estate | 2017 |
| Lapland Outfit Co. Oy | Wholesale & retail | 2025 |
| Lasi Manu Oy | Construction | 1995 |
| Lasso Technology Oy | Professional & scientific | 2017 |
| Lastenkirppis Nuppu Oy | Wholesale & retail | 2025 |
| Lautakylä Oy | Wholesale & retail | 2010 |
| LeeKoo Jukkola Oy | Health & social care | 2025 |
| Leenalan Huonekaluliike Ky | Wholesale & retail | 1986 |
| Leif Wentjärvi Oy | Transport & logistics | 2007 |
| Leikkaamo Oy | Other services | 2022 |
| Leikkihuone Kokkola avoin yhtiö | Arts & recreation | 2024 |
| Leikkimaa Oy | Arts & recreation | 2015 |
| Lepta Rakennus Oy | Construction | 2017 |
| Letku & Klemmari Holding Oy | Financial services | 2019 |
| Levin Tähtisilmä Oy Kittilä | Hospitality | 1999 |