| Macaulay Tree House Day Nursery | Bracebridge |
| Machar. Municipal Office | South River |
| MacKay Centre for Seniors | Goderich |
| MacLaren Art Centre, Art Classes and Day Camps for Children and Youth | Barrie |
| MacLaren Art Centre | Barrie |
| MacTier Food Bank | Georgian Bay Township |
| MADD Canada, Mailing Address, Barrie Simcoe Chapter | Barrie |
| Maggie's Resource Centre | Bancroft |
| Magnetawan Heritage Museum Centre, Magnetawan, Magnetawan Heritage Centre | Magnetawan |
| Magnetawan Lions Club, Magnetawan | Magnetawan |
| Magnetawan Public Library | Magnetawan |
| Magnetawan. Fire Department | Magnetawan |
| Magnetawan. Municipal Office | Magnetawan |
| Maitland Trail Association, Mailing Address | Goderich |
| Maitland Valley Conservation Authority, Wroxeter | Howick |
| Maitland Valley Conservation Authority, Wroxeter, Middle Maitland Rejuvenation Committee | Howick |
| Maitland Valley Family Health Team | Goderich |
| Maitland Valley Snowmobile Club | North Perth |
| Majestic Women's Institute, Huron East - Brussels Library | Huron East |
| Making Change, Mailing Address | Barrie |
| Manito Shriner's Club | Clearview (Simcoe County) |
| Manna Food Bank of Bracebridge | Bracebridge |
| Maplehill Wellness, Barrie, Foot Care | Barrie |
| Maplehill Wellness | Wasaga Beach |
| Mapleview Community Church, Barrie | Barrie |
| March of Dimes Canada, Barrie - Bryne Dr, Brain Injury Services - Outreach Activity Groups in Simcoe County | Barrie |
| March of Dimes Canada, Collingwood, Assisted Living Services and Low Acuity Services - Community Support Services Program | Collingwood |
| March of Dimes Canada, Homemaking Services, Collingwood | Collingwood |
| March of Dimes Canada, Midland, Assisted Living Services and Low Acuity Services - Community Support Services Program | Midland |
| March of Dimes Canada, Midland, Homemaking Services | Midland |
| March Of Dimes Canada - Midland, Midland, Community Support Services | Midland |
| March of Dimes Canada (GTA) | Toronto |
| March of Dimes Canada (MODC), Peterborough, Aphasia and Communication Disabilities (ACD) Program, Peterborough | Peterborough |
| Marchmont Baptist Church, Severn | Severn |
| Marine Heritage Society and Propeller Club | Saugeen Shores |
| Mariposa Grandmothers for Stephen Lewis Foundation (SLF) | Orillia |
| Mariposa House Hospice | Severn |
| Mariposa Place | Orillia |
| Markdale and District Food Bank, Christmas Assistance | Grey Highlands |
| Markdale and District Food Bank | Grey Highlands |
| Markdale Flesherton Senior Citizens Club | Grey Highlands |
| Markdale IDA Pharmacy | Markdale |
| Marlene's Foot Care | Clearview (Simcoe County) |
| Martin's School Transit | Owen Sound |
| Maryam Mosque | Oro-Medonte |
| Marycrest At Inglewood Seniors' Residence, Peterborough | Peterborough |
| Maryland Place | Peterborough |
| Masonic Lodge, Goderich | Goderich |
| Masonic Lodge, Carlow, Morningstar Clinton #309 | Ashfield-Colborne-Wawanosh |
| Masonic Lodge, Listowel Masonic Hall, Bernard Lodge 225 | Listowel |
| Masonic Lodge, Mitchell, Tudor 141 A.F. & A.M. | Mitchell |
| Masonic Lodge, St Marys, St James-Tecumseh Masonic Lodge No. 73 | St Marys |
| Matthews House, Community and Residential Hospice, Community Support Services, Home Healthcare | New Tecumseth |
| May Court Club of Barrie | Barrie |
| May Court Club of Barrie, Barrie | Barrie |
| May Court Club of Barrie, Barrie, May Court Shop | Barrie |
| MBA - Midland Basketball Association, Midland Mystics Girls' League and Midland Magic Boys' League | Midland |
| McConnell Club | St Marys |
| McConnell Foundation, Muskoka Distsrict | Bracebridge |
| McDonnel Street Activity Centre | Peterborough |
| McDougall. Fire Department | McDougall |
| McDougall. Municipal Office | McDougall |
| McIntosh Farms, Listowel Butcher Shop | North Perth |
| McKechnie Pharmacy | Kincardine (Town of) |
| McKellar Farm Producers Market, McKellar | Mckellar |
| McKellar Public Library | Mckellar |
| McKellar. Municipal Office, McKellar - Sharon Park Drive, McKellar Fire Department | Mckellar |
| McKellar. Municipal Office | Mckellar |
| McKenzie's Pharmacy - IDA | Wiarton |
| McMurrich / Monteith. Municipal Office | |
| McMurrich / Monteith. Municipal Office, Sprucedale Fire Hall, Volunteer Fire Department | |
| ME / FM Association of Peterborough and District, Peterborough | Peterborough |
| Meadow Creek Montessori School, Barrie - Cundles Rd E, Meadow Creek Montessori School - East | Barrie |
| Meadow Creek Montessori School, Barrie - Ferndale Dr N, Meadow Creek Montessori School - West | Barrie |
| Meadow Creek Montessori School, Shanty Bay, Meadow Creek Montessori School - The Bay | |
| Meaford Business Improvement Association | Meaford |
| Meaford Farmers' Market | Meaford (Town of) |
| Meaford Food Bank and Outreach, Christmas Assistance, Meaford | Meaford |
| Meaford Food Bank and Outreach, Meaford, Food Bank | Meaford |
| Meaford Food Bank and Outreach, Meaford | Meaford |
| Meaford Hall Arts & Cultural Centre | Meaford |
| Meaford IDA Pharmacy | Meaford (Town of) |
| Meaford Long Term Care Centre Auxiliary | Meaford |
| Meaford Public Library | Meaford |
| Meaford United Church | Meaford |
| Meaford. Municipal Office, Meaford Fire Department | Meaford |
| Meaford. Municipal Office, Meaford Moves+ | Meaford |
| Meaford. Municipal Office, Meaford Museum (The) | Meaford |
| Meaford. Municipal Office | Meaford |
| Meal on the Hill | West Grey |
| Meals On Wheels, Alliston | New Tecumseth |
| Meals on Wheels, Grand Valley | Grand Valley |
| Meaningful Movement, Mobile Service, In-Home Physiotherapy | Barrie |
| MED-E-OX, Goderich, Medical Equipment & Home Respiratory Ltd | Goderich |
| Mediation Centre of Simcoe County | Barrie |
| MedicAlert Foundation Canada | North York East |
| Medigas, Peterborough | Peterborough |
| Meeting Place (The), Orillia | Orillia |
| Meeting Place Tobermory (The), Community Food Programs | Tobermory |
| Meeting Place Tobermory (The) | Tobermory |
| Melancthon. Municipal Office | Melancthon |
| Melville Presbyterian Church | Huron East |
| Memorial Baptist Church, Kids' Church | Stratford |
| Memorial Baptist Church | Stratford |
| Mermigis (Dr Lambros) Psychologist | Barrie |
| Mete (Laurie Ann), Certified Advanced Foot Care | Springwater |
| Métis Nation of Ontario, Aging at Home Program | Peterborough |
| Métis Nation of Ontario, Barrie Office, Infinity Property Services - Rural Urban Indigenous Housing Program | Barrie |
| Métis Nation of Ontario, Owen Sound, Great Lakes Metis Council | Owen Sound |
| Métis Nation of Ontario, Owen Sound, Healing and Wellness Branch | Owen Sound |
| Métis Nation of Ontario - Georgian Bay Council - Midland, Education and Training, Midland | Midland |
| Métis Nation of Ontario - Georgian Bay Council - Midland, Healing and Wellness Program, Midland | Midland |
| Métis Nation of Ontario - Georgian Bay Council - Midland, Metis Healthy Babies, Healthy Children, Midland | Midland |
| Metroland Media | Barrie |
| Michael's Home Health Care, Bayfield | Bluewater |
| Michael's Pharmasave, Bayfield | Bayfield |
| Michael's Pharmasave, Michael's Pharmasave - Goderich | Goderich |
| Mid Huron Minor Hockey Association, Mailing Address | Central Huron |
| Middlesex Swimming | Stratford |
| Midhurst Ratepayers' Association | Springwater |
| Midland and District Business Women's Association | Midland |
| Midland Civitan Club, Midland | Midland |
| Midland Community Gardens, Midland Community Garden | Midland |
| Midland Horticultural Society | Midland |
| Midland Lions Club | Midland |
| Midland Midwives By the Bay | Midland |
| Midland Midwives By the Bay, Chigamik-Waypoint Community Health Hub | Midland |
| Midland Mountainview Family Co-operative, Midland | Midland |
| Midland Public Library, Food Pantry | Midland |
| Midland Public Library | Midland |
| Midland Sports Hall of Fame | Midland |
| Midland Town Crier | Midland |
| Midland, Penetanguishene and District Builders Association | Midland |
| Midland, Town of., Community Reach, Accessible Transit Service | Midland |
| Midland, Town of., Midland Penetanguishene Transit Service | Midland |
| Midland, Town of., Midland - Bayshore Dr, Fire Department | Midland |
| Midland, Town of., Midland - Dominion Ave, Municipal Office | Midland |
| Midland, Town of., Midland - Len Self Blvd - NSSRC, North Simcoe Sports and Recreation Centre | Midland |
| Midland, Town of., Midland Seniors Council, Midland - Len Self Blvd - NSSRC | Midland |
| Midland, Town of., No physical address, Rest Stations for Extreme Weather Relief | Midland |
| Midland-Penetanguishene District Community Emergency Response Team, Colborn St | Penetanguishene |
| Midwives Grey Bruce | Owen Sound |
| Midwives Nottawasaga | Collingwood |
| Midwives of Headwater Hills | Orangeville |
| Midwives of Muskoka, Bracebridge | Bracebridge |
| Military Family Resource Centre Meaford | Meaford |
| Mill Creek Care Centre, Long Term Care Facility | Barrie |
| Millbank Thrift Store | Perth East |
| Millbrook Agricultural Society | Cavan Monaghan |
| Millbrook Agricultural Society, Millbrook Fair | Cavan Monaghan |
| Millbrook and District Food Share, Food Bank | Cavan Monaghan |
| Millbrook Cavan Historical Society | Cavan Monaghan |
| Milverton Agricultural Society, Milverton Agri Centre | Perth East |
| Milverton and District Medical Centre | Perth East |
| Milverton and District Minor Softball, Mailing Address | Perth East |
| Milverton and District Snowmobile Club | Perth East |
| Milverton Christian Fellowship | Perth East |
| Milverton Curling Club | Perth East |
| Minden Food Bank | Minden Hills |
| Minden Hills. Municipal Office, By-Law, Building, Planning Department, Minden - Milne St | Minden Hills |
| Minden Hills. Municipal Office, Minden - 12418 Highway 35, Fire & Emergency Services Department | Minden |
| Minden Hills. Municipal Office, Minden - Milne St, Administrative Offices | Minden Hills |
| Minden Hills. Municipal Office, Minden - Parkside St, Community Services Department | Minden Hills |
| Minden Hills. Municipal Office, Minden - Public Works Administration Office, Public Works Department - Environmental Department | Minden |
| Minden Hills. Municipal Office, Minden - Public Works Administration Office, Public Works Department - Roads Department | Minden |
| Minden Hills. Municipal Office, Public Works Department, Minden - Milne St | Minden Hills |
| Mindful Kids Inc., Stratford | Stratford |
| MindWorks, Peterborough, Senior Respite and Enrichment Care Program | Peterborough |
| Ministry of Children, Community and Social Services (MCCSS), Stratford, Ontario Disability Support Program | Stratford |
| Minor Hockey Alliance of Ontario | Stratford |
| Mirror (The) | Midland |
| Mission Thrift Store, Cobourg | Cobourg |
| Mission Thrift Store - Barrie | Barrie |
| Mission Thrift Store (The) | Owen Sound |
| Mitchell & District Agricultural Society | West Perth |
| Mitchell and Area Community Outreach, Congregate Dining & Social Programs | West Perth |
| Mitchell and Area Community Outreach, Meals on Wheels | West Perth |
| Mitchell and Area Community Outreach, Wellness / Exercise program | West Perth |
| Mitchell and Area Community Outreach, Volunteer Transportation | West Perth |
| Mitchell and Area Community Outreach, West Perth - Various Locations, Exercise and Falls Prevention Group program | West Perth |
| Mitchell and Area Community Outreach, West Perth Transit | West Perth |
| Mitchell Business Improvement Area, Mitchell Business Improvement Area - Mailing Address Only | West Perth |
| Mitchell Curling Club | West Perth |
| Mitchell Family Doctors | West Perth |
| Mitchell Fish & Game Club | West Perth |
| Mitchell Horse Club | West Perth |
| Mitchell Legion Concert Band | West Perth |
| Mitchell Lions Club, Mailing Address Only | |
| Mitchell Lion's Park | West Perth |
| Mitchell Medical Pharmacy | Mitchell |
| Mitchell Minor Baseball | West Perth |
| Mitchell Minor Fastball | West Perth |
| Mitchell Minor Hockey | West Perth |
| Mitchell Minor Soccer | West Perth |
| Mitchell Minor Sports | West Perth |
| Mitchell Pioneer Hobby Association | West Perth |
| Mitchell Ringette | West Perth |
| Mitchell Skating Club, Mitchell Community Centre and Arena | West Perth |
| Mitchell Taxi | West Perth |
| Mnjikaning Fish Fence Circle | Orillia |
| Mobicare Advanced Foot Care | Barrie |
| Mobile Footcare Service, Bring Joy 2 Your Feet | Penetanguishene |
| Mobile Soup Kitchen, Community Pantry | Collingwood |
| Mobile Soup Kitchen | Collingwood |
| Model Ts, St Marys, Men's Hockey | St Marys |
| Modern College of Hairstyling and Esthetics | Barrie |
| Modern Healthcare Services | Innisfil |
| Mom's 4 Mom's Doula Services, No Physical Address | Oro-Medonte |
| Monarchist League Barrie Huronia Branch | |
| Monmouth Township Non-Profit Housing Corporation, Maple View | Wilberforce |
| Mono, Town of, Mono. Municipal Office | Mono |
| Montessori Children's House of Hanover | Hanover |
| Montgomery Bus Lines | North Huron |
| Mood Disorders Association of Ontario | Toronto |
| Moose Deer Point First Nation, Elder Services, Mobile Service | Mactier |
| Moose Deer Point First Nation, Fire Department, MacTier - 3687 Twelve Mile Bay Rd | Mactier |
| Moose Deer Point First Nation, Mactier - 1025C Mitawbik Rd, Health Services | Georgian Bay Township |
| Moose Deer Point First Nation, Mactier - 1025D Mitawbik Rd, Binoojii House Day Care Centre | Georgian Bay Township |
| Moose Deer Point First Nation, MacTier - 3720 Twelve Mile Bay Rd | Georgian Bay Township |
| Morris-Turnberry. Municipal Office, Brussels | Huron East |
| Mortgage Centre (The), Christmas Hamper Program | Collingwood |
| Motherwell Women's Institute, St Marys - Mailing Address | Perth South |
| Moving Towards Wellness Ltd, No Physical Address | Goderich |
| MS Canada, Durham Northumberland - Mailing Address, Durham Northumberland | Cobourg |
| MS Canada, Mailing Address, Barrie Support Group | Barrie |
| MS Canada, Online/Web Service, Virtual Support Groups | |
| MS Canada | Toronto |
| MTM Conservation Association, Tiny Marsh Nature Centre, Tiny Marsh Provincial Wildlife Area | Tiny |
| Mulcaster Mews | Barrie |
| Mulmur. Municipal Office | Mulmur |
| Mulmur-Melancthon Fire Department | Mulmur |
| Multicultural Association of Perth-Huron | Stratford |
| MulticulturalFirstAid.com | Cobourg |
| Multiple Births Canada | Richmond Hill |
| MultiSport Canada | Barrie |
| Municipal Animal Services | Cobourg |
| Municipal Office. Asphodel-Norwood, Fire Department - Station 1 (Norwood), Fire Department | Asphodel-Norwood |
| Municipal Office. Asphodel-Norwood | Asphodel-Norwood |
| Municipal Office. Asphodel-Norwood, Norwood Branch, Asphodel-Norwood Public Library | Asphodel-Norwood |
| Municipal Office. Asphodel-Norwood, Westwood Branch, Asphodel-Norwood Public Library | |
| Municipal Property Assessment Corporation, Trenton Assessment Field Office | Trenton |
| Municipality of Highlands East. Municipal Office, Bicroft Landfill Site, Landfill Sites | Highlands East |
| Municipality of Highlands East. Municipal Office, By-Law Department, Monck Rd - By-Law | Highlands East |
| Municipality of Highlands East. Municipal Office, Lloyd Watson Memorial Community Centre, Municipality of Highlands East. Muncipal Office | Highlands East |
| Municipality of Highlands East. Municipal Office, Lloyd Watson Memorial Community Centre, Recreation Department and Community Centres | Highlands East |
| Municipality of Highlands East. Municipal Office, Roads Department, Bicroft Landfill Site | Highlands East |
| Murray Street Baptist Church | Peterborough |
| Murray Street Baptist Church, Outreach Ministry | Peterborough |
| Murray's Windermere Gardens | Barrie |
| Muscular Dystrophy Canada - Ontario Regional Office | Toronto Downtown North |
| Museum on the Boyne | New Tecumseth |
| Music and Opera Appreciation Inc, Music and Opera Appreciation | Stratford |
| Music Therapy Services of Simcoe County, Barrie | Barrie |
| Muskoka Algonquin Healthcare, Bracebridge - Hiram Street, Diabetes Education Program | Bracebridge |
| Muskoka Algonquin Healthcare, Emergency Department, Huntsville District Memorial Hospital Site | Huntsville |
| Muskoka Algonquin Healthcare, Huntsville - 100 Frank Miller Dr - Howland Building, Diabetes Education Program | Huntsville |
| Muskoka Algonquin Healthcare, Huntsville District Memorial Hospital Site | Huntsville |
| Muskoka Algonquin Healthcare, Huntsville District Memorial Hospital Site, Muskoka District Stroke Centre | Huntsville |
| Muskoka Algonquin Healthcare, Obstetrics (Labour & Delivery), Huntsville District Memorial Hospital Site | Huntsville |
| Muskoka Algonquin Healthcare, Obstetrics (Labour & Delivery), South Muskoka Memorial Hospital - Bracebridge | Bracebridge |
| Muskoka Algonquin Healthcare, Ontario Breast Screening Program, Huntsville District Memorial Hospital Site | Huntsville |
| Muskoka Algonquin Healthcare, Ontario Breast Screening Program, South Muskoka Memorial Hospital - Bracebridge | Bracebridge |
| Muskoka Algonquin Healthcare, South Muskoka Memorial Hospital - Bracebridge, Seniors Assessment and Support Outreach Team | Bracebridge |
| Muskoka Algonquin Healthcare, South Muskoka Memorial Hospital - Bracebridge, South Muskoka Memorial Hospital Site | Bracebridge |
| Muskoka Ambulance Communications Service | Bracebridge |
| Muskoka Animal Rescue, Mailing Address | Huntsville |
| Muskoka Builders Association | Bracebridge |
| Muskoka Community Foundation, Bracebridge | Bracebridge |
| Muskoka Community Futures Development Corporation | Bracebridge |
| Muskoka Conservancy | Bracebridge |
| Muskoka District. Engineering and Public Works Department | Bracebridge |
| Muskoka District. Provincial Offences Office, Bracebridge, Ontario Court of Justice - The District Municipality of Muskoka | Bracebridge |
| Muskoka Drug Strategy Coalition | Barrie |
| Muskoka Family Focus and Children's Place | Bracebridge |
| Muskoka Family Focus and Children's Place, Bracebridge - McMurray St, Bracebridge Public School Children's Place | Bracebridge |
| Muskoka Family Focus and Children's Place, Bracebridge - Tamarack Trail, Bracebridge Children's Place | Bracebridge |
| Muskoka Family Focus and Children's Place, Gravenhurst, Gravenhurst Children's Place | Gravenhurst |
| Muskoka Family Focus and Children's Place, School Age Programs, Bracebridge - Entrance Dr | Bracebridge |
| Muskoka Family Network, Muskoka District - No physical address | |
| Muskoka Family Works, Huntsville, Muskoka Family Works Mediation and Relationship Coaching | Huntsville |
| Muskoka Field Naturalist Club, Muskoka - No Physical Address | Bracebridge |
| Muskoka Gentle Dental | Huntsville |
| Muskoka Heritage Place, Pioneer Village and Muskoka Museum | Huntsville |
| Muskoka Indigenous Friendship Centre | Gravenhurst |
| Muskoka Lakes Association | Muskoka Lakes Township |
| Muskoka Lakes Museum | Muskoka Lakes Township |
| Muskoka Lakes Preschool | Muskoka Lakes Township |
| Muskoka Lakes Property Management, Bracebridge - Mailing Address | Bracebridge |
| Muskoka Lakes. Municipal Office, Bala Branch, Muskoka Lakes Public Library, Bala Branch | Muskoka Lakes Township |
| Muskoka Lakes. Municipal Office, Port Carling - Joseph St, Muskoka Lakes Public Library, Port Carling Branch | Muskoka Lakes Township |
| Muskoka Lakes. Municipal Office, Port Carling - Lee Valley Dr, Muskoka Lakes. Fire Department | Muskoka Lakes Township |
| Muskoka Mobility and Car Service, Muskoka | Huntsville |
| Muskoka Music Centre, Huntsville | Huntsville |
| Muskoka North Residential | Gravenhurst |
| Muskoka Parry Sound Genealogy Group, Muskoka - No Physical Address | |
| Muskoka Parry Sound Sexual Assault Services, Bracebridge Office, Muskoka Parry Sound Sexual Assault Services, Bracebridge Office | Bracebridge |
| Muskoka Pride | |
| Muskoka Residential Centre | Severn |
| Muskoka Rock Minor Hockey | Muskoka Lakes Township |
| Muskoka Senior Assist, Mobile Service | Bracebridge |
| Muskoka Seniors | Huntsville |
| Muskoka Small Business Centre | Bracebridge |
| Muskoka Steamships & Discovery Centre, Gravenhurst - Steamship Bay Rd, Muskoka Discovery Centre | Gravenhurst |
| Muskoka Taxi | Gravenhurst |
| Muskoka Thunder Motorcycle Riders, Gravenhurst | Gravenhurst |
| Muskoka Tourette Syndrome Resource Unit, Bracebridge, Support Group | Bracebridge |
| Muskoka Tourism, Muskoka Tourism Marketing Agency | Gravenhurst |
| Muskoka Victim Services, Victim Crisis Assistance Ontario | Bracebridge |
| Muskoka Watershed Council | Bracebridge |
| Muskoka Women's Shelters and Services, Huntsville, Chrysalis | Huntsville |
| Muskoka Women's Shelters and Services, Muskoka Interval House, Bracebridge | Bracebridge |
| M'Wikwedong Indigenous Friendship Centre | Owen Sound |
| My Friend Beth Senior & Support Services, Collingwood | Collingwood |
| My Friend's House, Domestic Violence Shelter | Collingwood |
| My Grandfather's Cat, No Physical Address - Online Service | |
| My Organizer in Muskoka, Bracebridge - No Physical Address | Bracebridge |
| My Pre Academy | Barrie |
| My Sister's Place | New Tecumseth |
| MyHealth Centre, Huntsville, Cardiology and Ultrasound | Huntsville |
| Myrna Kiezer RNA, No physical address, Myrna Keizer RNA | Bracebridge |