M
- (Regional Municipality of Waterloo) Mannheim
- (Ottawa) Manordale
- (Ottawa) Manor Park
- (Ottawa) Manotick Station
- (Ottawa) Mansfield
- (Renfrew County) Mansfield
- (Dufferin County) Mansfield
- (Durham) Maple Beach
- (Middlesex County) Maple Grove
- (Durham) Maple Grove
- (Dufferin County) Maple Grove
- (United Counties of Leeds and Grenville) Maple Grove
- (Bruce County) Maple Hill
- (Frontenac County) Maple Hill
- (Parry Sound District) Maple Island
- (Haliburton County) Maple Lake
- (Oxford County) Maple Lake Park
- (Grey County) Maple Lane
- (Hastings County) Maple Leaf
- (District Municipality of Muskoka) Maple Ridge
- (Elgin County) Mapleton
- (Simcoe County) Maple Valley
- (Simcoe County) Maple Valley
- (Oxford County) Maplewood
- (Simcoe County) Mara Beach
- (Ottawa) Marathon
- (United Counties of Leeds and Grenville) Marble Rock
- (Ottawa) Marchhurst
- (Simcoe County) Marchmont
- (Wellington County) Marden