| ME Galanthus Ab | Administrative & support | 2017 |
| MESS, öppet bolag | Manufacturing | 2003 |
| Mianka OY AB | Health & social care | 2024 |
| MIARRO Oy Ab | Professional & scientific | 2024 |
| MLP-Invest Ab Oy | Arts & recreation | 2019 |
| MN Bygg och Spräng ab | Construction | 2024 |
| MN-Textil Oy Ab | Manufacturing | 1996 |
| MNE Holding Ab | Professional & scientific | 2011 |
| MR Flinck OY AB | Construction | 2022 |
| MR Media OY AB | Professional & scientific | 2009 |
| MS-Capital Oy | Financial services | 2015 |
| MTE Group Ab | Real estate | 2025 |
| MW Skogstjänst Ab | Agriculture & fishing | 1997 |
| Maanrakennus Sjöberg Oy | Construction | 2019 |
| Malmbacka Inöst Ab Oy | Financial services | 2010 |
| Marika Törnqvist Ab Oy | Health & social care | 2012 |
| Marilla Oy | Manufacturing | 2009 |
| Maritella kommandiittiyhtiö | Wholesale & retail | 1992 |
| Max's Lvi Lohja Oy | Construction | 2009 |
| MeRi Ventures Oy | Professional & scientific | 2015 |
| Melles Hälsoshop Ab Oy | Wholesale & retail | 2014 |
| Meremat Oy | Hospitality | 1994 |
| Meri Finland Oy | Transport & logistics | 2023 |
| Merino-Trading Oy Ab | Wholesale & retail | 2007 |
| Metallitekniikka R. Andersson Avoin Yhtiö | Manufacturing | 2008 |
| MiMaVest Ab | Financial services | 2020 |
| MiRos öppet bolag | Wholesale & retail | 2017 |
| Midix Kb | Arts & recreation | 1999 |
| Miekkasaari Oy | Professional & scientific | 2025 |
| Moldbusters Oy Ab | Construction | 2019 |
| Monvion Oy | Information & communication | 2026 |
| Motel-Marine Ky | Hospitality | 1965 |
| Mountainfox Oy | Financial services | 2022 |
| Multifoto Ab Oy | Information & communication | 2021 |
| Muuk.io Ab Oy | Information & communication | 2024 |
| Muutosvalmennus Reijo Kauppila Oy | Professional & scientific | 2005 |
| N.Nylund Invest OY AB | Real estate | 2016 |
| N2L GROUP Ab | Wholesale & retail | 2025 |
| NC Detailing Öppet bolag | Other services | 2015 |
| NC Training and Consulting Ltd Ab | Agriculture & fishing | 2013 |
| NO-Bygg Ab | Construction | 2013 |
| NablasLabs Oy | Information & communication | 2017 |
| Nacombe Oy | Wholesale & retail | 2001 |
| Nallus Kb Ky | Professional & scientific | 2005 |
| Nanomax International Oy | Real estate | 2004 |
| Nanomax Leasing Oy | Administrative & support | 2000 |
| Natural Works Oy | Professional & scientific | 2008 |
| Naturalife öppet bolag | Other services | 2011 |
| Navivision Oy | Professional & scientific | 2026 |
| Nelios Oy | Professional & scientific | 2005 |
| Nevarest Oy Ab | Hospitality | 1997 |
| Newland Development Oy | Real estate | 2020 |
| Nordheat Oy | Energy | 2024 |
| Nordic Bo Oy | Hospitality | 2024 |
| Nordicality Oy | Wholesale & retail | 2024 |
| Norra Hamnen Marina Oy Ab | Arts & recreation | 2026 |
| Norra Leksvalls Vattenandelslag | Water & waste | 2021 |
| Ny Våg Ab | Professional & scientific | 2025 |
| Ny-Bygg Ab Oy | Construction | 2024 |
| Nylands fiskeriförsäkringsförening | Financial services | 1939 |
| Nylunds Byggtjänst Öppet bolag | Construction | 2006 |
| Nymans Allvest Ab | Real estate | 2022 |
| Nyttab Ab | Information & communication | 1995 |
| O.K Business Consulting Oy | Professional & scientific | 2020 |
| OMT-Consulting Oy | Health & social care | 1996 |
| OY QuraZone AB | Wholesale & retail | 2009 |
| Ocean Construction Solutions Ab | Real estate | 2021 |
| Oliver Helander Oy | Arts & recreation | 2021 |
| Olofson Creative Oy Ab | Professional & scientific | 2011 |
| Omar Pizza Oy | Hospitality | 2022 |
| Oneone Ab | Wholesale & retail | 2014 |
| Open Payments Europe OY | Financial services | 2024 |
| Ordex Oy | Wholesale & retail | 2018 |
| Osakeyhtiö Kiinteistösaneeraus | Construction | 1973 |
| Osakeyhtiö Oky Doky Aktiebolag | Other services | 2019 |
| Oy Accnor Ab | Administrative & support | 2015 |
| Oy Anne-Maj Henriksson Ab | Wholesale & retail | 2001 |
| Oy Auratherm Ab | Construction | 1980 |
| Oy Axel Werner Ab | Real estate | 1976 |
| Oy Aztec Nordic Ltd Ab | Wholesale & retail | 1993 |
| Oy B W Trucks Ab | Mining & quarrying | 1994 |
| Oy Blue & White Service Ab | Construction | 1995 |
| Oy Brunström & Co Ab | Agriculture & fishing | 1990 |
| Oy Bryggeritomten Ab | Real estate | 1964 |
| Oy Bygg Ale Ab | Administrative & support | 2006 |
| Oy C-H Wikström Ab | Construction | 1979 |
| Oy Computerless Ab | Administrative & support | 1993 |
| Oy Concept Wines Ab | Wholesale & retail | 2008 |
| Oy Contrak Ab | Construction | 2017 |
| Oy Daniek Ab | Wholesale & retail | 1990 |
| Oy Edulogi Ab | Education | 1998 |
| Oy Eke - Marin Ab | Manufacturing | 1979 |
| Oy Ekenäs Svets Ab | Manufacturing | 1992 |
| Oy Ekenäs-Kylis Ab | Other services | 1997 |
| Oy Enko Trading Ab | Wholesale & retail | 2009 |
| Oy Fulmark Ab | Real estate | 2017 |
| Oy GZ Scandinavia Ab | Wholesale & retail | 2010 |
| Oy Gerco Ab | Real estate | 1973 |
| Oy H.A. Wikholm Ab | Real estate | 1982 |
| Oy Harry S. Lindholm Ab | Wholesale & retail | 1982 |