| Hair Company Anna & Mio avoin yhtiö | Other services | 1996 |
| Hair House Vasa Ab | Other services | 2023 |
| Hair Studios Torvi Oy Ab | Other services | 1987 |
| Haka-Suunnittelu Avoin yhtiö | Professional & scientific | 2005 |
| Hallipatruuna Oy | Real estate | 2009 |
| Hallitirehtöörit Oy | Real estate | 2006 |
| Halo Investments Ab Oy | Financial services | 2022 |
| HamFi Oy | Administrative & support | 2011 |
| HammasGroup Oy | Health & social care | 2025 |
| HammasGroupII Oy | Health & social care | 2025 |
| Hammaslaboratorio DentalArt Oy | Manufacturing | 2005 |
| Hammaslääkäripalvelut Pirhonen Oy | Health & social care | 2022 |
| Hamncharken Oy | Administrative & support | 1993 |
| Hampaat on Oy | Health & social care | 2022 |
| Handels Management Oy | Professional & scientific | 2026 |
| Hangö Energy Storage Oy | Energy | 2026 |
| Hangö Miljard Ab | Financial services | 2020 |
| Hanna K. Holding Oy | Financial services | 2024 |
| HansMedia ab/oy | Financial services | 2004 |
| Happy You Oy | Arts & recreation | 2010 |
| Harmonia Siivous Oy | Administrative & support | 2023 |
| Harrström Solar & Battery Ab | Energy | 2024 |
| Harrström vindpark Ab | Energy | 2013 |
| Hartman Järn Ab | Wholesale & retail | 1986 |
| Hartman Trading Oy Ab | Wholesale & retail | 2014 |
| Hauser Oy | Real estate | 2016 |
| Hautakivi Isokoski Oy | Manufacturing | 2021 |
| Havene Marin Avoin yhtiö | Manufacturing | 2009 |
| HeMi Asunnot Oy | Real estate | 2024 |
| HePa Invest Oy | Financial services | 2023 |
| HeTu Oy | Construction | 2023 |
| Healium Oy | Professional & scientific | 2025 |
| Heigen Oy | Wholesale & retail | 2020 |
| Heinola Invest Oy | Financial services | 1989 |
| Heiresses Avoin yhtiö | Other services | 2017 |
| Heliooz Ab | Professional & scientific | 2019 |
| Helminen Invest Oy | Professional & scientific | 1989 |
| HelmoLock Oy | Wholesale & retail | 2025 |
| Helsing Business Group Oy | Professional & scientific | 2024 |
| Helsingin Network Service Oy | Wholesale & retail | 1994 |
| Henelia Pizzeria Avoin yhtiö | Hospitality | 2026 |
| Hengittävä Oy | Real estate | 2023 |
| Henna K & Co Oy | Health & social care | 2021 |
| Henri Aalto Artist Oy | Arts & recreation | 2025 |
| Herkkuruletti Oy | Wholesale & retail | 2007 |
| Herlevi & Co Oy | Professional & scientific | 2015 |
| Herman Productions Ab Oy | Arts & recreation | 2022 |
| Hermans Snickeri Ab | Manufacturing | 2024 |
| Hersi Neuro Consulting Oy | Health & social care | 2025 |
| Herttalämpö Oy | Administrative & support | 1967 |
| Hevostoiminta Laukki Oy | Health & social care | 2021 |
| Hidden Project Oy | Wholesale & retail | 2016 |
| Hiekkapuhallus Lehmus Oy | Manufacturing | 1978 |
| Hietikko A&R Oy | Construction | 2020 |
| Hiltula Yhtiöt Oy | Financial services | 2010 |
| Hima Vaasa Oy LKV | Real estate | 2025 |
| Himainvest Oy | Financial services | 2012 |
| Hinaus Vaasa Oy | Other services | 2007 |
| Hinauspaja Vaasa Oy | Other services | 2022 |
| Hirsiunelma Oy | Construction | 2023 |
| Hitachi Energy Finland Oy | Manufacturing | 2019 |
| Hitunen Oy | Financial services | 2013 |
| Hitweld Oy | Professional & scientific | 2016 |
| Hjerpe Invest Oy | Financial services | 2012 |
| Hjerppe Capital Oy | Real estate | 2019 |
| Hockey-Team Vaasan Sport Oy | Arts & recreation | 2002 |
| Hogia Ferry Systems AB | Information & communication | 1982 |
| HoldCo Oy Liisalehdontie 12 | Real estate | 2016 |
| Holfin Oy | Financial services | 2026 |
| Holkon huolto- ja korjauspalvelut Oy | Other services | 2025 |
| Holma H. Property Oy | Professional & scientific | 2021 |
| Holmat Kiinteistöt Oy | Real estate | 2015 |
| Honkaistenranta Oy | Construction | 1997 |
| Hookea Oy | Information & communication | 2022 |
| Hoop Hair Ky | Other services | 2016 |
| Hopea Satama Oy | Real estate | 2019 |
| Hot Wings Vaasa Avoin Yhtiö | Wholesale & retail | 2015 |
| Hotel Astor Wasa Oy Ab | Hospitality | 1984 |
| Hotelli Gasthaus Ranta om. K ja M Turunen | Hospitality | 1989 |
| Hovi-Hotellit Oy | Hospitality | 2024 |
| Hovikruunu Oy | Real estate | 2013 |
| Hovikyyti Oy | Transport & logistics | 2022 |
| Hue & Ber öppet bolag | Hospitality | 2019 |
| Humbol Oy | Information & communication | 2021 |
| Hunton Oy/Ab | Wholesale & retail | 2014 |
| Huolel Vaasa Oy | Construction | 2023 |
| Huoltamo Kari Viita-aho kommandiittiyhtiö | Wholesale & retail | 1988 |
| Huutoniemen Pyörälinna Oy | Wholesale & retail | 2002 |
| Hyfer Foods Company Ab | Agriculture & fishing | 2022 |
| Hyrizeon Oy | Professional & scientific | 2025 |
| Hyvinvoiva Koira Oy | Other services | 2022 |
| Hyvä Tilaus Suomi Oy | Information & communication | 2004 |
| Hyytisen Talli Oy | Agriculture & fishing | 2019 |
| Häikäsee Holdings Oy | Financial services | 2026 |
| Hämeen Saneeraustyö Oy | Construction | 1990 |
| Hämäläinen Invest Oy | Professional & scientific | 2021 |
| Håkan Hjerpe Oy | Construction | 2010 |
| Höglandets Invest Oy | Financial services | 2015 |
| I & M Oikkonen Ky | Hospitality | 1988 |
| IA-Renovation Oy | Construction | 2019 |