| Evig Verk Oy | Construction | 2021 |
| Executive Labs Oy | Professional & scientific | 2026 |
| Express Hinauspalvelu Oy | Transport & logistics | 2015 |
| Express Huolto Oy Simo Jokinen | Administrative & support | 1998 |
| Femafinn OY | Hospitality | 2019 |
| Farmi Forest Oy | Manufacturing | 2020 |
| Fincon Metal Oy | Manufacturing | 2005 |
| Fincon Oy | Manufacturing | 2004 |
| Fine-kiinteistöt Oy | Real estate | 2017 |
| Fine-saneeraus Oy | Construction | 2017 |
| Finmade Oy | Information & communication | 2025 |
| Finnomec Oy | Manufacturing | 2006 |
| Foxman Oy | Manufacturing | 2021 |
| Frontier Health Oy | Health & social care | 2022 |
| Fysio-Symmetria Oy | Health & social care | 1984 |
| GPP Iisalmi Oy | Arts & recreation | 2019 |
| Gekko Iisalmi Oy | Wholesale & retail | 2021 |
| Genelec Oy | Manufacturing | 1978 |
| Green Pihapalvelu Oy | Construction | 2024 |
| H&S Piipponen Oy | Wholesale & retail | 2001 |
| Hamarfinn Ky | Hospitality | 2020 |
| HANZA Mechanics Iisalmi Oy | Manufacturing | 2004 |
| Hinaus & Kuljetus Rantonen Ky | Transport & logistics | 2002 |
| HJP Kehitys Oy | Professional & scientific | 2013 |
| HP-Rotacenter Oy | Manufacturing | 2016 |
| HR-Sports Oy | Arts & recreation | 2021 |
| HRPM-Investing Oy | Financial services | 2000 |
| HY Transport Oy | Transport & logistics | 1998 |
| Haapaniemen Matkailu Oy | Hospitality | 2006 |
| Haapaniemen Vuokramökit Oy | Hospitality | 2023 |
| Hakatemia Oy | Education | 2023 |
| Hallikolmoset Oy | Real estate | 2008 |
| Hammaslaboratorio Vesa Pölkki Oy | Manufacturing | 1983 |
| Hannas Hammas Oy | Health & social care | 2026 |
| Hautauspalvelu Sertti Oy | Other services | 2025 |
| Hay KRESST Oy | Wholesale & retail | 2018 |
| HeLean Oy | Professional & scientific | 2012 |
| Heeskanen Oy | Construction | 2026 |
| Heikki Lämpsä Ky | Wholesale & retail | 1982 |
| Helemijä sijoille Oy | Hospitality | 2011 |
| Hietalan Paja Oy | Real estate | 1970 |
| Hiidenhirvi Oy | Hospitality | 2001 |
| Hiskin Hirsi Oy | Wholesale & retail | 2010 |
| HoivaSavo Iisalmi Oy | Health & social care | 2023 |
| Honkakartano Oy | Wholesale & retail | 1990 |
| Huoltamo Nopari Oy | Wholesale & retail | 2019 |
| Huolto- ja konetyö RT Oy | Agriculture & fishing | 2023 |
| Huoltomega Oy | Other services | 2017 |
| Huonekaluliike M-Kalusto Ky | Wholesale & retail | 1966 |
| Huttu Finland Oy | Hospitality | 2023 |
| Hyvinvointi Virransilta Ky | Health & social care | 2011 |
| Hyvä Eväs Iisalmi Oy | Hospitality | 2015 |
| Hyvärisen Konepaja Ky | Manufacturing | 1985 |
| Hyvönen & Jauhiainen Oy | Agriculture & fishing | 2013 |
| Iikopa OY | Construction | 2019 |
| IIsalmen Kylmähuolto Oy | Construction | 2018 |
| ILICan Oy | Professional & scientific | 2019 |
| IPH-Isännöintipalvelut Oy | Real estate | 1997 |
| IPK Hockey Oy | Arts & recreation | 2020 |
| ITHM Talohuoltomestarit Oy | Administrative & support | 1996 |
| Idensielu Intialainen Ravintola Oy | Hospitality | 2025 |
| Ihalan Tupa ja Polku Oy | Health & social care | 2008 |
| Ihanat Kurvit Kommandiittiyhtiö | Wholesale & retail | 1997 |
| Iijärven Heinäkauppa Oy | Agriculture & fishing | 2023 |
| Iiprofit Oy | Wholesale & retail | 1992 |
| Iisalmen Akku Oy | Wholesale & retail | 2011 |
| Iisalmen Aluetaksi Oy | Transport & logistics | 1979 |
| Iisalmen Auto-Hyvönen Oy | Wholesale & retail | 1997 |
| Iisalmen Autoala Oy | Wholesale & retail | 2021 |
| Iisalmen Autokeskus Oy | Wholesale & retail | 1952 |
| Iisalmen Autokulma Oy | Wholesale & retail | 1993 |
| Iisalmen Automaalaamo Ky | Other services | 1989 |
| Iisalmen Autosompa Oy | Wholesale & retail | 2012 |
| Iisalmen Autotilaus Oy | Mining & quarrying | 1964 |
| Iisalmen Avainkaluste Oy | Wholesale & retail | 1995 |
| Iisalmen Citypörssi Ky | Wholesale & retail | 1992 |
| Iisalmen Diesel-osa Oy | Wholesale & retail | 2002 |
| Iisalmen Eco-Print Oy | Information & communication | 2017 |
| Iisalmen Elämyskeskus Oy | Hospitality | 2015 |
| Iisalmen Hammaspyörä Oy | Manufacturing | 1997 |
| Iisalmen Huoltokolmoset Oy | Manufacturing | 1987 |
| Iisalmen KVK-Kiinteistöt Oy | Real estate | 2010 |
| Iisalmen Kangastukku Avoin yhtiö | Wholesale & retail | 2009 |
| Iisalmen Kauppakulma Oy | Real estate | 1993 |
| Iisalmen Kiinnitystarvike Ky | Wholesale & retail | 1982 |
| Iisalmen Kiinteistöapu KY | Administrative & support | 1992 |
| Iisalmen Kiinteistöhuolto Korhonen Oy | Administrative & support | 1994 |
| Iisalmen Kiinteistövartiointi Oy | Administrative & support | 2018 |
| Iisalmen Kisakellari Oy | Education | 2015 |
| Iisalmen Kone-Esko Avoin yhtiö | Wholesale & retail | 1989 |
| Iisalmen Konekymppi, avoin yhtiö | Wholesale & retail | 1986 |
| Iisalmen Kopiokeskus ja Tarvikepalvelu Ky | Administrative & support | 1992 |
| Iisalmen Kuljetus Ky | Transport & logistics | 1981 |
| Iisalmen Kuormalavat Oy | Manufacturing | 2023 |
| Iisalmen Kuriirikuljetus Oy | Transport & logistics | 1993 |
| Iisalmen Kuva Avoin yhtiö | Professional & scientific | 2014 |
| Iisalmen Käyttöauto Ky | Wholesale & retail | 1995 |
| Iisalmen LVI-Säätö Oy | Construction | 1992 |
| Iisalmen Liikekeskus Oy | Real estate | 1992 |
| Iisalmen Metallirakenne Oy | Manufacturing | 1976 |