Ontario : M
- M'Chigeeng (1)
- Maberly (1)
- Mactier (6)
- Madoc (5)
- Magnetawan (2)
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- Mallorytown (1)
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- Maple (5)
- Marathon (10)
- Markdale (7)
- Markham (140)
- Marmora (2)
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- Massey (5)
- Matheson (2)
- Mattawa (2)
- Mattice (1)
- Maxville (1)
- Maxwell (1)
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- Meaford (8)
- Merlin (1)
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- Metcalfe (2)
- Midhurst (1)
- Midland (26)
- Mildmay (2)
- Millbank (1)
- Millbrook (3)
- Milton (22)
- Milverton (4)
- Minaki (2)
- Mindemoya (2)
- Minden (9)
- Mississauga (339)
- Mississaugua (3)
- Mitchell (4)
- Monetville (1)
- Monkland (1)
- Moonbeam (3)
- Moonstone (1)
- Moorefield (1)
- Moosonee (2)
- Morewood (1)
- Morpeth (2)
- Morrisburg (6)
- Morriston (2)
- Mount Albert (2)
- Mount Brydges (2)
- Mount Forest (7)
- Mount Hope (1)
- Mount Pleasant (1)
- Mountain (1)
- Muncey (1)
- Munster (1)