| Hehkufood Oy | Hospitality | 2021 |
| Hei.Ilo Oy | Wholesale & retail | 2026 |
| Heikin Saneeraus Oy | Construction | 1994 |
| Heikki Eskola Ky | Wholesale & retail | 1990 |
| Heikki Sainio International Ky | Wholesale & retail | 1986 |
| Heikki Tervonen Oy | Financial services | 2017 |
| Heinonsalo Oy | Wholesale & retail | 2007 |
| HelaStone Oy | Manufacturing | 1947 |
| Heli Koljonen Oy | Arts & recreation | 2021 |
| Helitech Oy | Transport & logistics | 1989 |
| Helletorppa Oy | Professional & scientific | 2019 |
| Helmiä Työyhteisölle Oy | Education | 2024 |
| Helsingin Autokorihuolto Oy | Real estate | 1946 |
| Helsingin Kattohuolto Oy | Construction | 2011 |
| Helsingin Tarvikeässät Oy | Other services | 1998 |
| Helylä Oy | Professional & scientific | 2014 |
| Hempeä Oy | Wholesale & retail | 2016 |
| Hentopuhallus Oy | Professional & scientific | 2025 |
| Hentox Oy | Financial services | 2025 |
| Hepe Trading Oy | Wholesale & retail | 2010 |
| Hertek-Tekniikka Oy | Wholesale & retail | 1987 |
| Hestic Invest Oy | Financial services | 1994 |
| Hetkitalli oy | Health & social care | 2019 |
| Hetkiä itsellesi Oy | Other services | 2025 |
| Hevision Oy | Professional & scientific | 2022 |
| Hevosmaa Consulting Oy | Professional & scientific | 2010 |
| Hicone Oy | Manufacturing | 2023 |
| Hienohomma Oy | Information & communication | 2009 |
| Hifi Guru Oy | Wholesale & retail | 1987 |
| High Four Productions Oy | Arts & recreation | 2021 |
| High Skill Oy | Professional & scientific | 2007 |
| Highflydiscs Oy | Wholesale & retail | 2024 |
| Hiidenkorpi Oy | Agriculture & fishing | 2009 |
| HimaInterior oy | Construction | 2024 |
| Hinaus Alamäki Oy | Transport & logistics | 2012 |
| Hinaus Pojat Oy | Transport & logistics | 1997 |
| Hinauskuljetus Sorvari Ky | Transport & logistics | 1989 |
| HippoRent Oy | Real estate | 2020 |
| Hirvonen Holding Oy | Financial services | 2014 |
| Hissikonsultit HS Oy | Construction | 2003 |
| Hissitek Oy | Construction | 2026 |
| Hitsaustyö Janhunen Oy | Manufacturing | 2022 |
| Hius & Kauneus Tähtitaivas Oy | Other services | 2017 |
| HiusStudio Uniikki Oy | Other services | 2006 |
| Hoitokoti Minnan Pirtti Ky | Health & social care | 2007 |
| HokSy Oy | Professional & scientific | 2025 |
| Hokalv Oy | Administrative & support | 2024 |
| Hokle Oy | Manufacturing | 1988 |
| Honkasport Oy | Arts & recreation | 1993 |
| HorsEvent Finland Oy | Arts & recreation | 2013 |
| Horsemania Oy | Arts & recreation | 2002 |
| Horsemaster Oy | Wholesale & retail | 2023 |
| Hostelli Palopuro avoin yhtiö | Hospitality | 2015 |
| Hotcom Oy | Financial services | 2002 |
| Hotel Hyvinkää Oy | Hospitality | 2023 |
| Housepro Talotekniikka Oy | Professional & scientific | 2015 |
| Hu-LVI Oy | Construction | 2025 |
| Hude Capital Oy | Financial services | 2025 |
| Huhtala Capital Oy | Real estate | 2020 |
| Huhtamäki Consulting Oy | Professional & scientific | 2014 |
| Huhtico Oy | Wholesale & retail | 1993 |
| Huippumyynti Oy | Education | 2020 |
| Humble Help Oy | Professional & scientific | 2026 |
| Husqtec Oy | Wholesale & retail | 2023 |
| Huttu Invest Oy | Professional & scientific | 2013 |
| Huvin ja Viihteen Oy | Arts & recreation | 2025 |
| HybridConst Oy | Construction | 2017 |
| Hymyä ja Hyvää Oloa Oy | Professional & scientific | 2025 |
| Hyper Oy | Construction | 1978 |
| Hyria Business Institute Oy | Education | 2012 |
| Hyria koulutus Oy | Education | 2009 |
| Hyria palvelut Oy | Hospitality | 2017 |
| Hysor Oy | Manufacturing | 1975 |
| Hyvi Cab Oy | Transport & logistics | 1997 |
| Hyvigolf Oy | Arts & recreation | 1987 |
| Hyvin Pesu Oy | Other services | 1974 |
| Hyvinkuivaus Oy | Construction | 2021 |
| Hyvinkää SecondHand Oy | Wholesale & retail | 2021 |
| Hyvinkään Ajo-opisto Oy | Education | 1996 |
| Hyvinkään Ajoneuvohuolto Oy | Other services | 2015 |
| Hyvinkään Asuntokeskus Oy | Real estate | 2012 |
| Hyvinkään Auto ja Kone Ky | Education | 1957 |
| Hyvinkään Auto ja Rakennuspalvelu oy | Construction | 2022 |
| Hyvinkään Autosport Oy | Wholesale & retail | 1972 |
| Hyvinkään Autovaraosa Oy | Wholesale & retail | 2022 |
| Hyvinkään Betoni Oy | Manufacturing | 1947 |
| Hyvinkään Clips Oy | Other services | 2012 |
| Hyvinkään Curlinghalli Oy | Arts & recreation | 2022 |
| Hyvinkään E-LVIS Oy | Wholesale & retail | 1994 |
| Hyvinkään Elokuva Oy | Information & communication | 1963 |
| Hyvinkään Foodartist Ky | Manufacturing | 1999 |
| Hyvinkään Fysioterapia Oy | Health & social care | 1995 |
| Hyvinkään HPP-Kiinteistöt Oy | Real estate | 1985 |
| Hyvinkään Harkkokatu 3 Oy | Real estate | 2020 |
| Hyvinkään Hevossairaala Oy | Professional & scientific | 2023 |
| Hyvinkään Hinausapu Oy | Transport & logistics | 1998 |
| Hyvinkään Hyvä Tennis Oy | Arts & recreation | 2001 |
| Hyvinkään Ilmastointi R Lappalainen Ky | Construction | 1990 |
| Hyvinkään Infra- ja talouskonsultit Oy | Professional & scientific | 2016 |
| Hyvinkään Isännöinti Oy | Real estate | 2011 |