| Konseptitoimisto Blocks Oy | Professional & scientific | 2014 |
| Konsepto Oy | Information & communication | 2024 |
| Konserttitoimisto Kumpulainen Oy | Arts & recreation | 2001 |
| Konserttituotanto Ferm & Huhdanpää Oy | Arts & recreation | 2020 |
| Konservointi Arkki Ky | Construction | 1994 |
| Konservointi- ja museopalvelut Lasse Mattila Oy | Arts & recreation | 2002 |
| Konservointi- ja restaurointiosuuskunta Korein | Construction | 2025 |
| Konservointiliike Patina Oy | Arts & recreation | 2012 |
| Konservointipalvelu Löytö oy | Arts & recreation | 2014 |
| Konsidered Oy | Professional & scientific | 2026 |
| Konsliik Oy | Professional & scientific | 2012 |
| Konsola Oy | Financial services | 2023 |
| Konsolinet Oy | Wholesale & retail | 2004 |
| Konsonanssi Oy | Health & social care | 2021 |
| Konst Hair & Gallery Oy | Other services | 2013 |
| Konst Hairdressers Oy | Other services | 2024 |
| Konsta Aittola Oy | Construction | 2022 |
| Konstan Möljä Oy | Hospitality | 2024 |
| Konstannin Kukka Oy | Wholesale & retail | 1992 |
| Konstinvest Oy | Financial services | 2022 |
| Konstrakt Oy | Professional & scientific | 2008 |
| Konstruktööri Lastunen Oy | Professional & scientific | 2021 |
| Konstsamfundet Ventures Ab | Financial services | 2008 |
| Konstsmide Finland Oy Ab | Wholesale & retail | 1982 |
| Konsu Oy | Professional & scientific | 1989 |
| Konsulantti Oy | Professional & scientific | 1982 |
| Konsulinsaari Oy | Financial services | 1993 |
| Konsultancy Oy | Professional & scientific | 2025 |
| Konsultointi Arttu Oy | Construction | 2008 |
| Konsultointi KAREG Oy | Professional & scientific | 1981 |
| Konsultointi Kari Kammonen Oy | Information & communication | 2020 |
| Konsultointi Martikainen Oy | Professional & scientific | 1988 |
| Konsultointi Momentum Oy | Professional & scientific | 2008 |
| Konsultointi Mosabacka Oy | Financial services | 2024 |
| Konsultointi Partanen R Oy | Administrative & support | 2024 |
| Konsultointi Puttonen Oy | Professional & scientific | 1974 |
| Konsultointi RT2904 Oy | Administrative & support | 1987 |
| Konsultointi Rönkä Oy | Professional & scientific | 2001 |
| Konsultointi Vesa Vesterinen Oy | Professional & scientific | 1991 |
| Konsultointi-Kapaset Oy | Professional & scientific | 1968 |
| Konsultointitoimisto Kirjava kana Oy | Information & communication | 1999 |
| Konsulttaani Oy | Professional & scientific | 2021 |
| Konsultti Ketonen Oy | Construction | 2020 |
| Konsultti- ja Rakennuspalvelu Raimo Kostiainen Oy | Professional & scientific | 1988 |
| Konsulttiryhmä Oy - Konsultgruppen Ab | Professional & scientific | 1973 |
| Konsulttitoimisto Auli Rihkanen Oy | Other services | 1991 |
| Konsulttitoimisto Connector Oy | Professional & scientific | 2003 |
| Konsulttitoimisto Ilkka Hämäläinen Oy | Professional & scientific | 1988 |
| Konsulttitoimisto Kolona Oy | Professional & scientific | 2017 |
| Konsulttitoimisto Kotoba oy | Professional & scientific | 2007 |
| Konsulttitoimisto Markku Holm Oy | Professional & scientific | 2010 |
| Konsulttitoimisto Mieli Mukana Oy | Education | 2011 |
| Konsulttitoimisto Otso Appelqvist Oy | Professional & scientific | 1983 |
| Konsulttitoimisto Pasi Sarinko Oy | Information & communication | 2009 |
| Konsulttitoimisto Pekka Luokkamäki Oy | Professional & scientific | 2003 |
| Konsulttitoimisto Pekka Somppi Oy | Professional & scientific | 2010 |
| Konsulttitoimisto Planpoint Oy | Professional & scientific | 1994 |
| Konsulttitoimisto Project Law Oy | Professional & scientific | 2008 |
| Konsulttitoimisto Virike Oy | Professional & scientific | 2008 |
| Konsulttiverkko Public Oy | Professional & scientific | 2021 |
| Kontio Capital Oy | Financial services | 2021 |
| Kontiolahden akku Oy | Energy | 2019 |
| Kontioniemen Hoiva Oy | Health & social care | 2023 |
| Kontioniemi Oy | Financial services | 1996 |
| Kontjuristo Ky | Professional & scientific | 1991 |
| Kontola Capital Oy | Financial services | 2019 |
| Kontraktori Group Oy | Professional & scientific | 2014 |
| Kontrib Oy | Professional & scientific | 2023 |
| Kontribuuttori OY | Financial services | 2015 |
| Kontrollipiste Oy | Other services | 2018 |
| Kontticom Oy | Wholesale & retail | 2025 |
| Konttinen Enterprises & Ventures Oy | Professional & scientific | 2024 |
| Konttorikeskus Koponen Oy | Wholesale & retail | 1997 |
| Kontu Arts Oy | Professional & scientific | 2019 |
| Kontu Group Oy | Professional & scientific | 2024 |
| Kontu Isännöinti Oy | Real estate | 2008 |
| Kontu Kioski Oy | Hospitality | 2026 |
| Kontu Tekniikka Oy | Professional & scientific | 2015 |
| Kontulan Burger Oy | Hospitality | 2002 |
| Kontulan Himabaari Oy | Hospitality | 2020 |
| Kontulan Huolto Oy | Real estate | 1964 |
| Kontulan Kello Ky | Wholesale & retail | 1967 |
| Kontulan Kukka Ky | Wholesale & retail | 1983 |
| Kontulan Lakitoimisto Oy | Professional & scientific | 2011 |
| Kontulan Optiikka Oy | Wholesale & retail | 2010 |
| Kontulan Suutari Oy | Other services | 2022 |
| Kontulan bisnes oy | Information & communication | 2024 |
| Kontunpesä Oy | Hospitality | 2013 |
| Konu Design Oy | Professional & scientific | 2026 |
| Konuon Oy | Financial services | 2023 |
| Konversium Oy | Information & communication | 2025 |
| Konverso Oy | Professional & scientific | 2023 |
| Konvertointi Group Oy | Professional & scientific | 2014 |
| Konvista Oy | Financial services | 2026 |
| Konvolv osk | Arts & recreation | 2019 |
| Konwell Group Oy Ab | Wholesale & retail | 2019 |
| Koo-Puu ja Kone Osakeyhtiö | Construction | 2004 |
| Kood Oy | Information & communication | 2019 |
| Koodaava arkkitehti Oy | Information & communication | 2021 |
| Koodakodit Oy | Real estate | 2023 |