| Medical Innovation Xchange | Other Public Sector Employers | 2025 | 1 | $220,049 |
| Medical Laboratory Professionals Association of Ontario | Other Public Sector Employers | 2023 | 1 | $128,758 |
| Medical Technology Association of Canada (O/A Medtech Canada) | Other Public Sector Employers | 2021 | 6 | $184,229 |
| Memorial Hospital, Bowmanville | Hospitals & Boards of Public Health | 1996 | 1 | $114,999 |
| Mennonite Brethern Senior Citizen Home | Other Public Sector Employers | 2025 | 2 | $117,052 |
| Mennonite Disaster Service Canada Inc | Other Public Sector Employers | 2024 | 1 | $109,245 |
| Mennonite Home Association | Other Public Sector Employers | 2010 | 3 | $110,067 |
| Mennonite Home Association of York Council Inc | Other Public Sector Employers | 2018 | 1 | $114,782 |
| Mennonite Home Association of York County | Other Public Sector Employers | 2025 | 10 | $131,492 |
| Mennonite Home Association of York Region | Other Public Sector Employers | 2015 | 2 | $113,627 |
| Mennonite New Life Centre of Toronto | Other Public Sector Employers | 2025 | 1 | $112,951 |
| Mental Health Connections | Other Public Sector Employers | 2025 | 1 | $101,962 |
| Mental Health Program Services | Other Public Sector Employers | 2025 | 1 | $113,457 |
| Mental Health Services - Hastings Prince Edward | Other Public Sector Employers | 2014 | 1 | $108,643 |
| Mental Health Services–Hastings | Other Public Sector Employers | 2012 | 1 | $105,306 |
| Meridian Spine and Joint Physiotherapy | Other Public Sector Employers | 2025 | 2 | $103,226 |
| Merit Openshop Contractors Association of Ontario | Other Public Sector Employers | 2025 | 4 | $150,047 |
| Merrickville DCHC | Other Public Sector Employers | 2000 | 4 | $117,848 |
| Merrickville District Community Health & Health Srvcs. Ctr. | Other Public Sector Employers | 2010 | 6 | $201,447 |
| Merrickville District Community Health & Services Centre | Other Public Sector Employers | 2009 | 5 | $185,222 |
| Merrickville District Community Health Centre | Other Public Sector Employers | 2006 | 4 | $143,686 |
| Merrymount Children's Centre | Other Public Sector Employers | 2025 | 5 | $113,856 |
| Meta Centre | Other Public Sector Employers | 2025 | 4 | $123,691 |
| Meta Vocational Services Inc | Other Public Sector Employers | 2025 | 1 | $117,410 |
| Metis Nation of Ontario | Other Public Sector Employers | 2016 | 3 | $114,982 |
| Metis Nation of Ontario Secretariat | Other Public Sector Employers | 2025 | 40 | $129,244 |
| Metis Voyageur Development Fund Inc | Other Public Sector Employers | 2025 | 4 | $148,587 |
| Metro Labour Education Centre | Other Public Sector Employers | 2025 | 3 | $109,787 |
| Metro Toronto Housing Authority | Crown Agencies | 1999 | 1 | $157,706 |
| Metro Toronto Housing Co Ltd. | Other Public Sector Employers | 1996 | 1 | $117,215 |
| Metro Toronto Housing Corporation | Crown Agencies | 2000 | 3 | $113,130 |
| Metro Toronto Library Board | Other Public Sector Employers | 1997 | 1 | $113,167 |
| Metro Toronto Movement for Literacy | Other Public Sector Employers | 2025 | 1 | $105,078 |
| Metro Toronto ZOO | Other Public Sector Employers | 1996 | 4 | $118,030 |
| Metrolinx | Crown Agencies | 2025 | 4,713 | $138,712 |
| Metropolitan Toronto and Region Conservation Authority | Other Public Sector Employers | 1996 | 1 | $104,672 |
| Metropolitan Toronto Convention Centre Corporation | Crown Agencies | 2025 | 72 | $144,330 |
| Metropolitan Toronto Housing Auth. | Crown Agencies | 1998 | 1 | $117,654 |
| Metropolitan Toronto Housing Authority | Other Public Sector Employers | 1996 | 1 | $108,768 |
| Metropolitan Toronto Library Board | Other Public Sector Employers | 1996 | 1 | $116,279 |
| Metropolitan Toronto School Board | School Boards | 1997 | 8 | $125,280 |
| MetropolitanToronto Police Service | Other Public Sector Employers | 1996 | 10 | $118,288 |
| MH Windsor Essex County Branch | Hospitals & Boards of Public Health | 2005 | 2 | $111,750 |
| Michael Garron Hospital | Hospitals & Boards of Public Health | 2025 | 749 | $129,590 |
| Michener Insitute for Applied Health Sciences | Other Public Sector Employers | 2006 | 5 | $139,820 |
| Michener Inst. for Applied Health Sci. | Other Public Sector Employers | 1997 | 1 | $124,541 |
| Michener Inst. for Applied Health Services | Other Public Sector Employers | 2003 | 3 | $123,102 |
| Michener Inst. for Applied Hlth. Sci. | Other Public Sector Employers | 2005 | 4 | $133,906 |
| Michener Instit. for App. Hlth Science. | Other Public Sector Employers | 2002 | 2 | $126,696 |
| Michener Instit. for App.Hlth Science | Other Public Sector Employers | 2000 | 2 | $128,319 |
| Michener Institute for Applied Health | Other Public Sector Employers | 1998 | 1 | $131,546 |
| Michener Institute for Applied Hlth | Other Public Sector Employers | 1999 | 2 | $119,431 |
| Michener Institute of Education at Uhn | Other Public Sector Employers | 2025 | 61 | $125,426 |
| MICS Group of Health Srvcs | Hospitals & Boards of Public Health | 2004 | 1 | $132,755 |
| MICS Group of Hlth. Srvcs. | Other Public Sector Employers | 2004 | 1 | $132,755 |
| MICS Group of Hospitals - Matheson | Hospitals & Boards of Public Health | 1997 | 1 | $106,000 |
| MICsGroup of Health Services | Hospitals & Boards of Public Health | 2003 | 2 | $116,689 |
| Middlesex Community Living | Other Public Sector Employers | 2025 | 2 | $129,258 |
| Middlesex County Board of Education | School Boards | 1996 | 1 | $110,173 |
| Middlesex County Library | Municipalities & Services | 2011 | 1 | $115,813 |
| Middlesex – London Health Unit | Hospitals & Boards of Public Health | 2025 | 40 | $133,701 |
| Mill Creek Care Centre | Other Public Sector Employers | 2025 | 3 | $111,855 |
| Mills Community Support Corporation | Other Public Sector Employers | 2016 | 1 | $118,524 |
| Mills Community Support Corporation Inc | Other Public Sector Employers | 2025 | 5 | $129,953 |
| Milton Cardiac Care Ltd. | Other Public Sector Employers | 2025 | 1 | $102,914 |
| Milton Community Resource Centre | Other Public Sector Employers | 2014 | 1 | $107,550 |
| Milton Public Library | Other Public Sector Employers | 2016 | 2 | $139,522 |
| Mind Forward Brain Injury Services Ontario | Other Public Sector Employers | 2025 | 5 | $118,638 |
| Mines | Government of Ontario – Ministries | 2024 | 132 | $123,462 |
| Mining Innovation Rehab and Applied Research Corp | Other Public Sector Employers | 2016 | 1 | $123,309 |
| Ministry of Economic Development and Growth/Ministry of Research, Innovation and Science | Government of Ontario – Ministries | 2018 | 210 | $124,443 |
| Ministry of Economic Development and Growth/Ministry of Research, Innovation and Science / Ministère du Développement économique et de la Croissance / Ministère de la Recherche, de l'Innovation et des Sciences | Government of Ontario – Ministries | 2017 | 177 | $117,699 |
| Ministry of Housing | Government of Ontario – Ministries | 2018 | 48 | $117,537 |
| Ministry of Infrastructure | Government of Ontario – Ministries | 2018 | 64 | $124,916 |
| Minto-Mapleton Family Health Team | Other Public Sector Employers | 2023 | 3 | $116,634 |
| Minwaashin Lodge – Indigenous Women's Support Centre | Other Public Sector Employers | 2025 | 3 | $132,336 |
| Misiway Milopemahtesewin CHC | Other Public Sector Employers | 2000 | 1 | $141,106 |
| Misiway Milopemahtesewin Community Health Centre | Other Public Sector Employers | 2025 | 4 | $125,606 |
| Mission Services of Hamilton Inc | Other Public Sector Employers | 2025 | 5 | $120,226 |
| Mission Services of London | Other Public Sector Employers | 2025 | 4 | $116,111 |
| Mississauga Board of Trade | Other Public Sector Employers | 2009 | 1 | $116,539 |
| Mississauga First Nation | Other Public Sector Employers | 2025 | 3 | $105,398 |
| Mississauga Halton Community Care Access Centre | Other Public Sector Employers | 2016 | 40 | $122,109 |
| Mississauga Hospital | Hospitals & Boards of Public Health | 1997 | 6 | $133,386 |
| Mississauga Integrated Care Centre | Other Public Sector Employers | 2025 | 14 | $127,163 |
| Mississauga Italian Canadian Benevolent Association | Other Public Sector Employers | 2025 | 11 | $122,711 |
| Mississauga Parent-Child Resource Centres | Other Public Sector Employers | 2015 | 1 | $112,490 |
| Mississaugas of Scugog Island First Nation | Other Public Sector Employers | 2022 | 8 | $140,348 |
| Mississaugas of the Credit First Nation | Other Public Sector Employers | 2025 | 5 | $110,773 |
| Mississaugas of the New Credit First Nation | Other Public Sector Employers | 2018 | 2 | $105,546 |
| Mississippi Valley Conservation Authority | Other Public Sector Employers | 2021 | 4 | $117,636 |
| Mitaanjigamiing First Nation | Other Public Sector Employers | 2024 | 2 | $118,887 |
| Mitacs Inc. | Other Public Sector Employers | 2016 | 4 | $117,222 |
| Miziwe Biik Development Corporation | Other Public Sector Employers | 2025 | 2 | $148,785 |
| Mnaasged Child and Family Services | Other Public Sector Employers | 2024 | 1 | $111,755 |
| Mohawk College of Applied Arts and Technology | Colleges | 2025 | 594 | $130,799 |
| Mohawk Council of Akwesasne | Other Public Sector Employers | 2024 | 9 | $128,868 |
| Mohawk Shared Services Inc. | Other Public Sector Employers | 2015 | 13 | $142,126 |
| Mohawks of the Bay of Quinte | Other Public Sector Employers | 2025 | 5 | $112,135 |
| Momiji Health Care Society | Other Public Sector Employers | 2025 | 3 | $130,450 |