| Modepipe OY | Construction | 2011 |
| Moe 1 OY | Transport & logistics | 2026 |
| MOLDFINN Group oy | Transport & logistics | 2022 |
| MOM ESPOO Oy | Wholesale & retail | 2011 |
| MONC Oy | Professional & scientific | 2015 |
| Monditaly Wines and Spirits OY | Wholesale & retail | 2012 |
| MOP-Laskenta Oy | Professional & scientific | 2011 |
| Morgantina International Brand Management OY | Households | 2022 |
| MORO:Rakennus.OY | Construction | 2020 |
| MOTORA Oy | Administrative & support | 2023 |
| MP Communications Oy | Information & communication | 2023 |
| MP Kone ja Rakennus Oy | Construction | 1993 |
| MP ZenRobotics Oy | Information & communication | 2022 |
| MP-IT Computers Oy | Wholesale & retail | 2004 |
| MP-Investments Oy | Real estate | 2017 |
| MP-Laskenta Ky | Professional & scientific | 1994 |
| MPH HEADGEAR Oy | Wholesale & retail | 2008 |
| MPH-Rakennus Oy | Construction | 1992 |
| MPI-Rakennus Oy | Construction | 1990 |
| MPT Group Oy | Financial services | 2023 |
| MPT Urakointi OY | Construction | 2023 |
| MPV-Group Oy | Construction | 2012 |
| MR Kasakka Oy | Construction | 2022 |
| MR Kodit Oy | Real estate | 2015 |
| MR Lasku OY | Professional & scientific | 2020 |
| MR Logistic Oy | Transport & logistics | 2016 |
| MR Puusepät OY | Construction | 2017 |
| MR Talot Oy | Construction | 2018 |
| MR-Fin Team Oy | Construction | 2021 |
| MR-Insinöörit Oy | Professional & scientific | 1997 |
| MR-Visualize Oy | Professional & scientific | 2011 |
| MRA-Perustukset Oy | Construction | 2014 |
| MRC Global (Finland) Oy | Wholesale & retail | 2007 |
| MS Finance Oy | Financial services | 2023 |
| MS24 Consulting Oy | Wholesale & retail | 2016 |
| MSA Consulting Oy | Professional & scientific | 2008 |
| MSE Studio Oy Ab | Information & communication | 2010 |
| MSH Finland Oy | Administrative & support | 2013 |
| MSH-Service OY | Construction | 2026 |
| MSL Invest Oy | Financial services | 2022 |
| MSM Rakennus Oy | Construction | 2024 |
| MSP Holding Oy | Financial services | 2023 |
| MSV Tape Oy | Professional & scientific | 2021 |
| MT Finland Oy | Information & communication | 2022 |
| MT Palvelut Oy | Construction | 1998 |
| MT Personnel Oy | Administrative & support | 2008 |
| MT Webstores Oy | Wholesale & retail | 2025 |
| MT-Autosähkö Oy | Other services | 2009 |
| MT-Loghouses Oy | Wholesale & retail | 2013 |
| MT-Työt Oy | Construction | 2024 |
| MTA-Timanttityöt oy | Real estate | 2021 |
| Mtab Suomi OY | Transport & logistics | 2015 |
| MTF Service Oy | Professional & scientific | 2022 |
| MTN Palvelut Oy | Administrative & support | 2020 |
| MTV Infinity Oy | Financial services | 2018 |
| Munmun OY | Hospitality | 2025 |
| Mustaphan Puu OY | Administrative & support | 2019 |
| MV Gastro Oy | Hospitality | 2020 |
| MV yhtiöt oy | Construction | 1990 |
| MV-Jäähdytys Oy | Construction | 2012 |
| MVH Group Oy | Administrative & support | 2021 |
| MVJA Group Oy | Financial services | 2018 |
| MVP Solutions Oy | Information & communication | 2025 |
| MVP tilitoimisto oy | Professional & scientific | 2020 |
| MVR Palvelut Oy | Real estate | 2018 |
| MVT-Rentals Oy | Administrative & support | 2017 |
| MVtaksi Oy | Transport & logistics | 2013 |
| MW Works Oy | Professional & scientific | 2026 |
| MWAmax Oy | Wholesale & retail | 2024 |
| MX Events Oy | Arts & recreation | 2021 |
| MX Sisustus Oy | Construction | 2014 |
| MZ Corporation Oy | Hospitality | 2024 |
| MZ Enterprise Oy | Hospitality | 2022 |
| MaHoita Oy | Professional & scientific | 2025 |
| MaHu Holding Oy | Professional & scientific | 2021 |
| MaLe oy | Construction | 2022 |
| MaS Consulting Oy | Professional & scientific | 2023 |
| Maa Company Oy | Construction | 2016 |
| Maailmanparantaja Oy | Education | 2013 |
| Maakarin monitoimipalvelut oy | Construction | 2023 |
| Maalaamo AutoFix Avia Oy | Other services | 2012 |
| Maalaamo Tapio Kokko Oy | Construction | 1977 |
| Maalarinet Oy | Construction | 2011 |
| Maalaus Kennet Grönholm Oy | Construction | 2002 |
| Maalaus Metsänheimo Oy | Construction | 2019 |
| Maalaus Ranex Oy | Construction | 2019 |
| Maalaus ja Saneeraus Haverinen Oy | Construction | 1997 |
| Maalaus ja Saneeraus Selma Oy | Construction | 2008 |
| Maalaus ja remontti Hirvonen Oy | Construction | 2007 |
| Maalaus- ja saneerauspalvelu Valkeasalo Oy | Construction | 2009 |
| Maalaus-Tervo Oy | Construction | 2021 |
| Maalausilo Oy | Construction | 2025 |
| Maalausliike A. Räty Ky | Construction | 1985 |
| Maalausliike Ilkka Saario Oy | Construction | 1993 |
| Maalausliike Jari T. Nurminen Oy | Construction | 1990 |
| Maalausliike Kemppainen Oy | Construction | 2009 |
| Maalausliike Painted Oy | Construction | 2012 |
| Maalausliike Simsalabim Oy | Construction | 2022 |
| Maalausliike T. Aspegren Oy | Construction | 1988 |
| Maalausliike T. Pynnönen Oy | Construction | 1996 |