- Marathon
- Mattawa
- Midland
- Markham
- Meaford
- Merrickville-Wolford
- Minto
- Mississauga
- Mississippi Mills
- Mono
- Moosonee
- Mount Brydges
- Maberly
- MacDonald Bay
- MacDonald Beach
- Maceys Bay
- Macksville
- MacLennan
- MacTier
- Macton
- Madawaska
- Madoc
- Maecks Subdivision
- Mafeking
- Magnetawan
- Magnetic Island
- Main Duck Island
- Mainsville
- Maitland
- Malahide