| Kaunolan sähkövarasto Oy | Energy | 2023 |
| Kaupinpuisto Oy | Professional & scientific | 2022 |
| Kaupland Oy | Wholesale & retail | 2010 |
| Kauppa Osakeyhtiö | Wholesale & retail | 1918 |
| Kauppahallikorttelin kehitys Oy | Real estate | 2022 |
| Kauppahallin konditoria ja leipämyymälä Oy | Wholesale & retail | 2017 |
| Kauppahallin korttelin ystävät Oy | Financial services | 2022 |
| Kauppahuone Agency Oy | Wholesale & retail | 2020 |
| Kauppahuone Arto Heino Oy | Real estate | 1984 |
| Kauppahuone Härkänen Oy | Financial services | 2024 |
| Kauppahuone Kentia Oy | Wholesale & retail | 1992 |
| Kauppahuone Kotola Oy | Financial services | 1999 |
| Kauppahuone Luomala Oy | Wholesale & retail | 2025 |
| Kauppahuone Luostarinen Oy | Wholesale & retail | 2023 |
| Kauppahuone O. Forsman Oy | Wholesale & retail | 1986 |
| Kauppahuone Olkinuora & Pedersen Oy | Wholesale & retail | 2015 |
| Kauppahuone Ormio Oy | Professional & scientific | 2021 |
| Kauppahuone Paronen Oy | Wholesale & retail | 2018 |
| Kauppahuone Polynova Oy | Wholesale & retail | 1996 |
| Kauppahuone Rantala Oy | Wholesale & retail | 2006 |
| Kauppahuone Salmenkylä Oy | Professional & scientific | 1991 |
| Kauppahuone Sirén Oy | Wholesale & retail | 1993 |
| Kauppahuone Tuovinen Ky | Professional & scientific | 2017 |
| Kauppakeskus REDI GP Oy | Financial services | 2014 |
| Kauppakeskus Seppä Oy | Real estate | 1964 |
| Kauppakeskus Skanssi Oy | Real estate | 2007 |
| Kauppakeskuskiinteistöt FEA Ky | Financial services | 2006 |
| Kauppaki Oy | Wholesale & retail | 2023 |
| Kauppakirjat von Pfaler Oy | Professional & scientific | 2022 |
| Kauppamainos Oy | Financial services | 1946 |
| Kauppatalo R & A Oy | Wholesale & retail | 2019 |
| Kauppatorin Hammaskeskus Oy | Health & social care | 2002 |
| Kauppatorin Taloushallinto Oy | Professional & scientific | 2005 |
| Kauppatorin Torimimmit avoin yhtiö | Wholesale & retail | 2009 |
| Kauppayhtiö Haka Oy | Real estate | 1987 |
| Kauppiasbroidit Oy | Wholesale & retail | 2023 |
| Kaupunki Diners Oy | Hospitality | 2025 |
| KaupunkiPyörä Suomi Oy | Transport & logistics | 2016 |
| KaupunkiPyörä Vantaa Oy | Administrative & support | 2019 |
| Kaupunkikehitys Oy | Professional & scientific | 1984 |
| Kaupunkilounaat Oy | Information & communication | 2022 |
| Kaupunkitutkimus TA Oy | Professional & scientific | 2001 |
| Kauri Capital Oy | Professional & scientific | 2024 |
| Kaurilan sauna Oy | Manufacturing | 2019 |
| Kausal Oy | Information & communication | 2020 |
| Kausalan Energia Oy | Energy | 2019 |
| Kause Capital Oy | Financial services | 2024 |
| Kausi Oy | Professional & scientific | 2022 |
| Kausihuolto Oy | Administrative & support | 2024 |
| Kausiomena Oy | Manufacturing | 2020 |
| Kauttu & Co Oy | Other services | 2022 |
| Kauvanto Oy | Real estate | 2022 |
| Kavacap Oy | Administrative & support | 2022 |
| Kavadi Oy | Professional & scientific | 2004 |
| Kavadi tilitoimisto Oy | Professional & scientific | 2023 |
| Kavantsaari Capital Oy | Administrative & support | 2022 |
| Kavea Oy | Administrative & support | 2021 |
| Kaveri Productions | Information & communication | 2022 |
| Kaveri hitsausmestari Oy | Construction | 2023 |
| Kaverinen Oy | Professional & scientific | 2002 |
| Kaveriontti Oy | Administrative & support | 2021 |
| Kavest Oy | Financial services | 2005 |
| Kavipin Oy | Construction | 1992 |
| Kawaii Nightmares Oy | Other services | 2022 |
| Kawata Oy | Arts & recreation | 2023 |
| Kaya Brothers Oy | Hospitality | 2024 |
| Kayaman Islands Oy | Information & communication | 2023 |
| Kayiwa Oy | Professional & scientific | 2007 |
| Kazakstan Finland Consulting Oy Ltd | Professional & scientific | 1987 |
| Kb B.V.V. Westerlund Ky | | 1980 |
| Kb Bengt Ahlfors Comedia Ky | Arts & recreation | 1979 |
| Kb GS-Autoservice Ky | Wholesale & retail | 1985 |
| Kb TIC Technology Imports & Consulting ky | Wholesale & retail | 1990 |
| KeKo - Catering Oy | Hospitality | 2011 |
| KeTaKi Group Oy | Information & communication | 2026 |
| Kebab Master Oy | Hospitality | 2025 |
| Kebu The Döner Company Oy | Hospitality | 2021 |
| Kebumies Oy | Hospitality | 2021 |
| Kecy Taksipalvelu Oy | Transport & logistics | 2026 |
| Kedarnath Oy | Hospitality | 2023 |
| Kedev Oy | Financial services | 2020 |
| Kedjekrans Oy | Information & communication | 2018 |
| Keele Oy | Financial services | 1990 |
| Keep Cool Tiimi Oy | Information & communication | 1991 |
| Keep It Wheel Oy Ltd | Arts & recreation | 2017 |
| Keep it Simple KiS Oy Ab | Professional & scientific | 2012 |
| Keepdev Oy | Information & communication | 2015 |
| Keeplis Trading Oy | Wholesale & retail | 2025 |
| KeerthiCon Oy | Professional & scientific | 2025 |
| Keeta Holding Oy | Administrative & support | 2022 |
| Kehaista Oy | Financial services | 2024 |
| Kehita AI Oy | Information & communication | 2025 |
| Kehitin Oy | Professional & scientific | 2013 |
| Kehittyvä Metsä Oy | Agriculture & fishing | 2020 |
| Kehittäjät Yhtymä Oy | Administrative & support | 1989 |
| Kehittämispalvelut Annika Juonela Oy | Education | 2003 |
| Kehityspalvelut Tillman Oy | Professional & scientific | 2004 |
| Kehityspiikki Oy | Professional & scientific | 2001 |
| Kehitystyö Paavo Viirkorpi Ky | Professional & scientific | 2008 |
| Keho Fitness Oy | Wholesale & retail | 2021 |