| Korpitieto Oy | Agriculture & fishing | 2026 |
| Kosken Louhinta Ky | Construction | 1990 |
| Koukutti Oy | Manufacturing | 2025 |
| Kukkaromäentila Oy | Agriculture & fishing | 2026 |
| Kuljetus Marko Kauppinen Oy | Manufacturing | 1990 |
| Kuljetus Tuomo Kosunen Ky | Transport & logistics | 1990 |
| Kuljetus Ursin Oy | Transport & logistics | 2018 |
| Kuljetusliike Ari Tanninen Oy | Transport & logistics | 1981 |
| Kuljetusliike Arto Aholainen Oy | Transport & logistics | 1992 |
| Kuormaus Ursin Oy | Transport & logistics | 2010 |
| Kuusisaaren Randek Oy | Construction | 2009 |
| L&L dyno oy | Other services | 2021 |
| LK Porras Oy | Manufacturing | 1974 |
| Larida Oy | Hospitality | 2007 |
| Lasijannu Oy | Construction | 2018 |
| Laskenta- ja Rakentajapalvelu Hirviniemi Oy | Real estate | 2000 |
| Lattialämpö Ville Niskanen Oy | Wholesale & retail | 2013 |
| Lehtonen & Lehtoset Oy | Health & social care | 2002 |
| Leppäsalo Metsä Oy | Agriculture & fishing | 2025 |
| Leppävirran Autohuolto ja -tarvike Oy | Other services | 1996 |
| Leppävirran Itsepalvelupesula Ky | Other services | 1981 |
| Leppävirran Kiinteistö Oy | Real estate | 1988 |
| Leppävirran Kirjapaino Ky | Manufacturing | 1987 |
| Leppävirran Kolarityökeskus Oy | Other services | 2020 |
| Leppävirran Korona Kiinteistöt Oy | Real estate | 2010 |
| Leppävirran Kukka- ja Hautauspalvelu S. Kinnunen Ky | Other services | 1985 |
| Leppävirran Kuljetuskumppanit Oy | Construction | 1993 |
| Leppävirran Kumikorjaamo Ky | Wholesale & retail | 1987 |
| Leppävirran Kuntoutuspalvelu Oy | Health & social care | 1985 |
| Leppävirran Lekomet Oy | Manufacturing | 1986 |
| Leppävirran Liikenneasema Oy | Hospitality | 2023 |
| Leppävirran Monitoimitalo Oy | Real estate | 2013 |
| Leppävirran Murena Oy | Professional & scientific | 2009 |
| Leppävirran Ostoskeskus Oy | Real estate | 1976 |
| Leppävirran Talopalvelut Oy | Administrative & support | 2012 |
| Leppävirran Terästuote Ky | Manufacturing | 1980 |
| Leppävirran Tilikeskus Oy | Professional & scientific | 2012 |
| Leppävirran Virkistysuimala Leppäkerttu Oy | Arts & recreation | 1993 |
| Leppävirran tuoremarja- ja vihannesmyynti Oy | Transport & logistics | 2024 |
| Link Fashion Oy | Wholesale & retail | 2017 |
| Lixuan Oy | Hospitality | 2024 |
| Lokapalvelu Siili Oy | Water & waste | 2001 |
| Louhintavaruste Vihavainen Ky | Wholesale & retail | 1982 |
| MPJ-Kiinteistöt Oy | Real estate | 2017 |
| MT Huoltamo Oy | Wholesale & retail | 2015 |
| Maalaus Kröger Oy | Construction | 2025 |
| Maanrakennus Sakari Koponen Ky | Construction | 1988 |
| Maansiirto Jarmo Ollikainen Oy | Construction | 2016 |
| Maansiirto Veljekset Nissinen, avoin yhtiö | | 1975 |
| Malviala Group Oy | Professional & scientific | 1983 |
| Mansikkamäen osuuskunta | Agriculture & fishing | 2017 |
| Markkinointitoimisto Markkinarako Ky | Professional & scientific | 2012 |
| Matuvo Oy | Administrative & support | 2009 |
| Megaro oy | Hospitality | 2021 |
| Metsä- ja sahauspalvelu Kopone Oy | Agriculture & fishing | 2024 |
| Metsä-Peku Oy | Agriculture & fishing | 1987 |
| Metweld Ky | Manufacturing | 2006 |
| Metwelding Oy | Manufacturing | 2019 |
| Mika Konttinen Oy | Transport & logistics | 2013 |
| Miniravintola Oy | Hospitality | 2022 |
| Mino's Home Oy | Real estate | 2019 |
| Mittasähkö Oy | Construction | 2021 |
| Muotola Ky | Manufacturing | 2000 |
| Muotouma Ky | Professional & scientific | 2013 |
| Mäntyahon hevospalvelut Oy | Other services | 2026 |
| Nerko Oy | Construction | 2006 |
| Niuro Yhtiöt Oy | Real estate | 2022 |
| Ollikainen Infra Oy | Construction | 2018 |
| Oskari Monni Ky | Wholesale & retail | 2009 |
| Oy Savo Sport Center (SSC) | Wholesale & retail | 2007 |
| Oy Well Manpak Ab | Manufacturing | 1989 |
| P.K. Auringonpimennys Oy | Manufacturing | 1997 |
| P.P.J. Leinonen Ky | Other services | 1985 |
| PT Energia Poraus Oy | Construction | 2011 |
| Parmaco Production Oy | Construction | 2012 |
| Peccco Oy | Financial services | 2023 |
| Pekkonen Group Oy | Construction | 2025 |
| Pemiko Oy | Transport & logistics | 2014 |
| Pertemet Oy | Manufacturing | 2019 |
| Perttu Laitinen Ky | Wholesale & retail | 2016 |
| Pipemaster Oy | Construction | 2024 |
| Pippurimuori Oy | Other services | 1996 |
| Pivaset Oy | Manufacturing | 2022 |
| Pizzeria Leppävirta avoin yhtiö | Hospitality | 2011 |
| Pohjolan Paasto & Hyvinvointi Oy | Other services | 2025 |
| RS-Lattiat Oy | Construction | 2011 |
| RST-Trans Ky | Transport & logistics | 1996 |
| Rakennus Kauhanen Oy | Construction | 1988 |
| Rakennusliike Erkki Keinänen Ky | Construction | 1991 |
| Rakennustyö Martti Nyyssönen Oy | Construction | 1985 |
| Ramutek Oy | Construction | 1994 |
| Rauno O. Pasanen Ky | Wholesale & retail | 2000 |
| Risen Monipalvelu Oy | Construction | 2014 |
| SAT Pro Oy | Financial services | 2021 |
| SE-8 Motorfix Ky | Other services | 2015 |
| SK Dry Oy | Professional & scientific | 2023 |
| SKM Stainless Oy | Manufacturing | 2018 |
| SP-Vuokraus Oy | Administrative & support | 2020 |
| Salaojaexpertit oy | Construction | 2026 |
| Savohalli Oy | Construction | 2023 |