| Grizzly Minded Oy | Administrative & support | 2025 |
| H Arajärvi Oy | Transport & logistics | 1987 |
| H-kukkakauppa ky | Wholesale & retail | 2018 |
| HH Tedra Oy | Manufacturing | 2021 |
| HL-Rakennusratkaisut Oy | Construction | 2011 |
| HS-Kiinteistöt Oy | Real estate | 2024 |
| HS-Metalli Oy | Manufacturing | 2024 |
| HTL-Works Oy | Manufacturing | 2005 |
| Hakalantie34osk | Real estate | 2016 |
| Halli B Oy | Real estate | 2025 |
| Hallirakenne J. Kuisma Oy | Manufacturing | 1991 |
| Hanilla Oy | Hospitality | 2021 |
| Hanna Salminen Ky | Wholesale & retail | 2015 |
| Hannan Huone oy | Health & social care | 2026 |
| Haraki Oy | Hospitality | 2020 |
| Hastema Oy | Wholesale & retail | 2001 |
| Havuco Ky | Professional & scientific | 1993 |
| Headshop Group Oy | Administrative & support | 2018 |
| Heinäkankaan Konepalvelu Ky | Construction | 2013 |
| Helmihuolto Oy | Administrative & support | 2024 |
| Hez Consulting Oy | Professional & scientific | 2023 |
| Hez Properties Oy | Real estate | 2025 |
| Highgrade logistics Ky Kylmäkoski | Professional & scientific | 1992 |
| Highhill Invest Oy | Real estate | 2022 |
| Hilkka Huhtala om. Riitta Vähäkuopus Ky | Wholesale & retail | 1967 |
| Hillova Oy | Professional & scientific | 2025 |
| Hissimestarit Oy | Construction | 2018 |
| Hitsound Oy | Professional & scientific | 1988 |
| Hiuskeskus Tea Oy | Other services | 2019 |
| Hiusstudio Art Oy | Other services | 2019 |
| Hiusstudio JB Lakka Oy | Other services | 2007 |
| Hoitola Lumo Oy | Other services | 2008 |
| Hoiva Anniina Oy | Health & social care | 2026 |
| Holma Ky | Wholesale & retail | 1987 |
| Holvasti Clean Oy | Administrative & support | 1997 |
| Huhtala Oil Oy | Wholesale & retail | 2017 |
| Huhtala Power Oy | Energy | 2014 |
| Hulvaton Oy | Arts & recreation | 2020 |
| Humppilan Kalliopuisto Oy | Real estate | 1988 |
| Hundeeraus & Fundeeraus Oy | Other services | 2026 |
| Hämeen Sähkö OY | Construction | 2003 |
| Hämeen Hyvät Matkat ky | Administrative & support | 2010 |
| Hämeen Koti- ja Siivouspalvelu oy | Administrative & support | 2020 |
| Hämeen Rakennusteam Oy | Construction | 2005 |
| Hämeen Tuotepalvelu Oy | Wholesale & retail | 1996 |
| Hämeen Turistiauto Oy | Transport & logistics | 1987 |
| Hämeen Venttiilihuolto Oy | Manufacturing | 1991 |
| Hämeentien Pizza & Kebab avoin yhtiö | Hospitality | 2021 |
| Hölkkä SBS Oy | Manufacturing | 2017 |
| ILA-Kiinteistöt Oy | Real estate | 2016 |
| ITU Maatalouspalvelut Oy | Agriculture & fishing | 2017 |
| Ikicode Oy | Information & communication | 2021 |
| Ikkala Trade Oy | Wholesale & retail | 2010 |
| Ikkuna-asennus Lilvanen Oy | Construction | 2013 |
| Ikkunapirkka Ky | Construction | 2000 |
| Ilmakas Oy | Professional & scientific | 2014 |
| Ilveskosken Oy | Wholesale & retail | 2023 |
| Imous Safety Oy | Administrative & support | 2024 |
| Insigno Oy | Wholesale & retail | 2018 |
| Insima Oy | Manufacturing | 1999 |
| Insinööritoimisto Matti Laine Oy | Professional & scientific | 2008 |
| Interventus Oy | Wholesale & retail | 1977 |
| Ipanaria Oy | Health & social care | 2022 |
| Ipeka Automation Oy | Manufacturing | 1987 |
| Irjakki Oy | Real estate | 1987 |
| Isohaavisto Oy | Administrative & support | 2009 |
| Isännöinti Kartio Oy | Real estate | 2015 |
| Itävalvonta Räty Ky | Administrative & support | 1983 |
| Ivlicum Oy | Health & social care | 2023 |
| J Base-Engineering Oy | Manufacturing | 1998 |
| J.A. Välimäki Oy | Manufacturing | 2010 |
| J.B.F Machine Tech Oy | Manufacturing | 2024 |
| Jarno Aaltonen Ky | Construction | 2006 |
| Javanmiri Avoin Yhtiö | Hospitality | 2020 |
| JC-tekniikka Oy | Construction | 1993 |
| Jiipee Invest OY | Real estate | 2000 |
| JJ Mechanics OY | Manufacturing | 2018 |
| JK-Rakennustyö Oy | Construction | 2012 |
| JKA Investments Oy | Financial services | 2017 |
| JM Kiinteistösijoitus Oy | Real estate | 2021 |
| JM Maxx Oy | Wholesale & retail | 2005 |
| JMJ HOLDING Oy | Financial services | 2024 |
| JMN Autohuolto Oy | Other services | 2015 |
| JNE Account Oy | Financial services | 2025 |
| JOPRA Oy | Real estate | 1980 |
| JP-Rautarakenne Oy | Manufacturing | 1990 |
| JS Lääkäripalvelut Oy | Health & social care | 2022 |
| JS-Talonrakennus Oy | Construction | 2008 |
| JTL Partners Oy | Professional & scientific | 2024 |
| JTP Kiinteistöt Oy | Real estate | 2021 |
| JV Palokatko Oy | Construction | 2023 |
| Jaakkimanpojan Energia Oy | Energy | 2008 |
| Jaakko Väisänen Oy | Construction | 2014 |
| Jaakkorinki Oy | Transport & logistics | 2018 |
| Jaakolan Tila Oy | Agriculture & fishing | 2024 |
| Jacob&Smooth Finland Oy | Professional & scientific | 2023 |
| Jakorinki Ky | Transport & logistics | 1995 |
| Jalbetravels Oy | Health & social care | 2020 |
| Jalkahoitola Jalkapohja Oy | Health & social care | 2004 |
| Jarale Oy | Construction | 2021 |