| Hampton-Media Oy | Information & communication | 2019 |
| Hannu Hietanen Oy | Wholesale & retail | 2011 |
| Hansaset Oy | Wholesale & retail | 2009 |
| Hansun Kiska H. Romu Ky | Wholesale & retail | 1994 |
| Happy Spiders Oy | Wholesale & retail | 1982 |
| Hapu Service Oy | Other services | 2025 |
| Harkon Oy | Administrative & support | 2021 |
| Harvester.works Staffing Oy | Administrative & support | 2021 |
| HauStudio Oy | Other services | 2026 |
| Haulavia Oy | Financial services | 2021 |
| Hausjärven Eristys ja Ilmastointi Oy | Construction | 1993 |
| Havu Hovi Oy | Hospitality | 2024 |
| Hawage Oy | Information & communication | 1997 |
| Hayakom Oy | Professional & scientific | 2020 |
| Hehkuva sydän Oy | Manufacturing | 2020 |
| Heinäveden Kesät Oy | Administrative & support | 2015 |
| Helmi Ommel Osk | Administrative & support | 2019 |
| Helminen Logistiikkapalvelut Oy | Transport & logistics | 2021 |
| Helppo Yhtiöt Oy | Wholesale & retail | 2016 |
| Helsingin Kattopalvelu Oy | Construction | 2013 |
| Henkilötyö Jokinen Oy | Transport & logistics | 2021 |
| Herajoen Kuljetus Oy | Transport & logistics | 2011 |
| Herajoen Talli Ky | Real estate | 1987 |
| Heras Finland Oy | Construction | 2022 |
| Heras Group Finland Oy | Professional & scientific | 2023 |
| Hesaplast Oy | Wholesale & retail | 1981 |
| Hessun Auto- ja Konekorjaamo avoin yhtiö | Other services | 2008 |
| Hihhi Hahhaa Oy | Transport & logistics | 2019 |
| Hiivola Vuokraus Oy | Real estate | 2019 |
| Hinaus Happo Oy | Transport & logistics | 2024 |
| Hinauspalvelu Seiti Oy | Transport & logistics | 2016 |
| Hirsitehti Oy | Wholesale & retail | 2026 |
| Hoivasisustus Oy | Wholesale & retail | 2015 |
| Holistic Hoof Boots Oy | Education | 2021 |
| Hollolan Lasilogistiikka Oy | Transport & logistics | 1997 |
| Hoof2Horse Oy | Education | 2026 |
| Horiwitch Productions Oy | Arts & recreation | 2023 |
| Horizon Next Solutions Oy | Education | 2021 |
| Hovi Training Center Oy | Education | 2026 |
| Huldat Oy | Real estate | 2021 |
| Humiseva Consulting Oy | Professional & scientific | 2023 |
| Hunajakivi Oy | Real estate | 2018 |
| Huolto ja Asennus A.Leinonen oy | Other services | 2022 |
| Huolto- ja saneerauspalvelut Katajainen Oy | Construction | 2019 |
| Hy-Ka Oy | Financial services | 2004 |
| Hyvinkään Artemis Oy | Professional & scientific | 1997 |
| Hyvinkään Autotukku Oy | Wholesale & retail | 1995 |
| Hyvinkään Design Avoin yhtiö | Professional & scientific | 2002 |
| Hyvinkään Mattokeskus Oy | Wholesale & retail | 1989 |
| Hyvinkään Mikromet Oy | Manufacturing | 1991 |
| Hyvinkään viher- ja maanrakennus Oy | Construction | 2022 |
| Hyvänolonhoitola AQVAMARIINI OY | Other services | 2007 |
| Häme Ateriat Oy | Health & social care | 2025 |
| Häme Food Oy | Health & social care | 2011 |
| Hämeen Maansiirto Oy | Construction | 2024 |
| Hämeen Metsäenergia Oy | Wholesale & retail | 1989 |
| Hämeen Metsäpalvelu Oy | Agriculture & fishing | 2024 |
| Hämeen Moniosaajat Oy | Other services | 2014 |
| Hämeen Monitoimitilit Oy | Professional & scientific | 1973 |
| Hämeen Pizza Max Oy | Hospitality | 1991 |
| Hämeen Rakennus- ja Saneeraus Oy | Construction | 2013 |
| Hämeen Vuokrakone Oy | Administrative & support | 2006 |
| Hämeforest Oy | Agriculture & fishing | 2023 |
| Härkönen Capital Oy | Financial services | 2020 |
| Höptsöp Entertainment Ab | Professional & scientific | 2020 |
| IM Finland Oy | Construction | 2019 |
| IT'smy Oy | Information & communication | 2007 |
| IV-Huolto Supponen Oy | Construction | 2014 |
| Ilastinen Oy | Wholesale & retail | 2015 |
| Ilkka Kuittinen Ky | Wholesale & retail | 1986 |
| Ilkka Metsäterä Ky | Professional & scientific | 1976 |
| Ilkka Tamlander Ky | Manufacturing | 1986 |
| Ilmalämpöpumppu osaajat oy | Construction | 2024 |
| Ilmalämpöpumppuhuolto Sääskilahti Oy | Construction | 2025 |
| Ilmatila Oy | Construction | 1999 |
| Ilora Oy | Wholesale & retail | 2026 |
| Ilves-halli Oy | Financial services | 2004 |
| Incipere Oy | Professional & scientific | 2025 |
| Infra Park Oy | Real estate | 2016 |
| Infrahäme Oy | Construction | 2025 |
| Infraport Oy | Professional & scientific | 2006 |
| Infraverstas Oy | Professional & scientific | 2015 |
| Innolion Oy | Information & communication | 2012 |
| Insinööritoimisto JRM Oy | Professional & scientific | 1990 |
| Insinööritoimisto M. Koskivuori Oy | Professional & scientific | 1993 |
| Inspire 'ur Dog Training Oy | Arts & recreation | 2015 |
| Interim Executive Services Oy | Professional & scientific | 2021 |
| Island of Sales Oy | Professional & scientific | 2020 |
| Isojoen Steelman Oy | Real estate | 2002 |
| Isotalo Kiinteistöt Oy | Real estate | 2007 |
| Isännöinti Isotalo Oy | Real estate | 2013 |
| Isännöitsijätoimisto Esa Friman Oy | Real estate | 2001 |
| Isännöitsijätoimisto Paras Talo Oy | Real estate | 1987 |
| Itavet Oy | Professional & scientific | 2012 |
| Ixtriim Oy | Professional & scientific | 2019 |
| J Hanni Oy | Construction | 2012 |
| J&J Rauta Oy | Wholesale & retail | 2018 |
| J. Brandt Ky | Transport & logistics | 1999 |
| J. Tengman Oy | Arts & recreation | 2000 |
| JARMI-RAK Oy | Construction | 2008 |