| GolfHuone Oy | Arts & recreation | 2020 |
| Golla Oy | Manufacturing | 1994 |
| Good Fellas Oy | Administrative & support | 2025 |
| Grami Oy | Construction | 2007 |
| Grand Aurora Properties Oy | Professional & scientific | 2023 |
| Granwall oy | Construction | 2022 |
| Gratax Oy | Transport & logistics | 2004 |
| Graxse Oy | Professional & scientific | 2023 |
| Gridetor Oy | Wholesale & retail | 2001 |
| Grilli 2000 Oy | Hospitality | 1999 |
| Gromov & Hakala Oy | Education | 2011 |
| H&D taksiliikenne palvelu Oy | Transport & logistics | 2020 |
| H-H Advisory & Consulting Oy | Professional & scientific | 2026 |
| H-INK Oy | Professional & scientific | 2020 |
| H. Saarinen Ky | Hospitality | 1994 |
| HA Sähkö & Auto Ab Oy | Other services | 2025 |
| Heavyinstall OY | Manufacturing | 2014 |
| HEJA-Invest Oy | Real estate | 2010 |
| HELSS-Invest Oy | Financial services | 2021 |
| HJ-Stable Ky | Agriculture & fishing | 2001 |
| HJKK - Steel Oy | Manufacturing | 1994 |
| HK siivoo Oy | Administrative & support | 2024 |
| HL Management Oy | Financial services | 2024 |
| HLS Group Oy | Manufacturing | 2022 |
| HR Tekos Oy | Administrative & support | 2004 |
| HTManangement Oy | Arts & recreation | 2022 |
| HTT Beauty Oy | Other services | 2026 |
| HV-Group Oy | Manufacturing | 1990 |
| HW-Hunt Oy | Manufacturing | 1989 |
| Haaponiemi Infra Oy | Construction | 2019 |
| Hackspeed Oy | Transport & logistics | 2012 |
| Hairplan Oy | Other services | 2019 |
| Hakaroof Oy | Construction | 2025 |
| Haliaeetus Oy Ab | Real estate | 2011 |
| Hall Expert Oy | Construction | 2009 |
| Hallix Finland Oy | Manufacturing | 2019 |
| Haltius Oy | Professional & scientific | 2015 |
| Hamm Trading Oy | Professional & scientific | 1978 |
| Hammasklinikka Rytivaara Oy | Health & social care | 2022 |
| Hammaslaboratorio Alvident Oy | Manufacturing | 2019 |
| Hammaslaboratorio X-iDent Oy | Manufacturing | 2010 |
| Hammaslääkäri Jaana Holm Oy | Health & social care | 2021 |
| Hammaslääkäri Sari Björkroth Oy | Health & social care | 2016 |
| Hammasmakasiini Oy | Health & social care | 2020 |
| HanKi Rauta Oy | Wholesale & retail | 2025 |
| Handymen Hohenthal avoin yhtiö | Administrative & support | 2005 |
| Hankintaratas Oy | Professional & scientific | 2020 |
| Hannu Kaitaluoma Oy | Professional & scientific | 1995 |
| Hans Company Oy | Wholesale & retail | 2008 |
| Hantek sähkö oy | Construction | 2023 |
| Happydealers Avoin yhtiö | Wholesale & retail | 2014 |
| Harjun Leipomo Oy | Manufacturing | 1995 |
| Hartam Asiantuntijapalvelut Oy | Professional & scientific | 2026 |
| Hartam Oy | Professional & scientific | 2018 |
| Hassel Rakennus Ab Oy | Construction | 2013 |
| Haukka Bidco Oy | Financial services | 2025 |
| Haukka Topco Oy | Financial services | 2025 |
| Hautakivityöt Peltoniemi Oy | Manufacturing | 2021 |
| Hautamäki Invest Oy | Financial services | 2019 |
| Hautaustoimisto Mattsson Oy | Other services | 2006 |
| Heavy Duty Hydraulic Oy | Manufacturing | 1994 |
| Hejmarin Ratsutila Oy | Arts & recreation | 2021 |
| Heliostorage Oy | Manufacturing | 2020 |
| Helkavuori Oy | Construction | 2021 |
| Helmi solutions Oy | Information & communication | 2024 |
| Henkilöstövuokraus RM Oy | Administrative & support | 2023 |
| Henry J Hagström Ab-Oy | Manufacturing | 1980 |
| Henry Rekilä Oy | Wholesale & retail | 1984 |
| Herkkuhetki Kentala Oy | Hospitality | 2026 |
| Herlefix Oy | Other services | 2026 |
| Hexa Holding Oy | Financial services | 2023 |
| Hilla Group Oyj | Information & communication | 1919 |
| Hilla Media Oy | Transport & logistics | 2014 |
| Hilvie Holding Oy | Financial services | 2024 |
| Hitsaus ja Laadunvalvonta Störling Oy | Manufacturing | 2025 |
| Hitsauspalvelu P.Pietilä Oy | Manufacturing | 2025 |
| Hiussali Piilo Oy | Other services | 2019 |
| Hiutale Aerials Oy | Professional & scientific | 2013 |
| HoivaPalvelu Anahata Oy | Health & social care | 2021 |
| Holta-Invest Oy | Administrative & support | 2024 |
| Honkatien Lämpö Oy | Energy | 1965 |
| HotaDent Oy | Health & social care | 2025 |
| Houltinki Oy | Financial services | 1987 |
| Hoviapu Oy | Manufacturing | 2017 |
| Huhtala Partners Oy | Professional & scientific | 2023 |
| Huima Oluthuone Oy | Hospitality | 2017 |
| Huolto & Hitsaus Päivinen Oy | Manufacturing | 2019 |
| Huoltoasema Anneli Wikman Ky | Wholesale & retail | 1993 |
| Huoltoasema Koutonen Oy | Wholesale & retail | 1987 |
| Huoltoasema Markus Savonen Ky | Wholesale & retail | 1995 |
| Huoltopalvelu J.Tiala Oy | Other services | 2024 |
| Huoma Palvelut Oy | Professional & scientific | 2023 |
| Huopanan turkis avoin yhtiö | | 1981 |
| Hutt-Bazar Oy | Wholesale & retail | 2023 |
| HybCo Oy | Professional & scientific | 2007 |
| Hycamite TCD Technologies Oy | Manufacturing | 2020 |
| Hyllymix Oy | Wholesale & retail | 1951 |
| Hypofeel Oy Ab | Financial services | 2015 |
| Hypohealth Oy | Arts & recreation | 2024 |
| Häjy Freight Oy | Transport & logistics | 2009 |