M
- (Thunder Bay District) Millar
- (District Municipality of Muskoka) Millar Hill
- (Renfrew County) Millars Corner
- (United Counties of Leeds and Grenville) Millars Corners
- (Bruce County) Millarton
- (Perth County) Millbank
- (Hastings County) Millbridge
- (Oxford County) Milldale
- (Bruce County) Miller Lake
- (Lennox and Addington County) Millers Corner
- (Lennox and Addington County) Millhaven
- (Ottawa) Mills Corners
- (Hastings County) Milltown
- (Lennox and Addington County) Milsap
- (Perth County) Milverton
- (Rainy River District) Minahico
- (Kenora District) Minaki
- (Manitoulin District) Mindemoya
- (Haliburton County) Miners Bay
- (Simcoe County) Minesing
- (District Municipality of Muskoka) Minett
- (Renfrew County) Mink Lake
- (Kenora District) Minnitaki
- (Hastings County) Minto
- (Frontenac County) Mississippi Station
- (Frontenac County) Missouri
- (Perth County) Mitchell
- (Elgin County) Mitchell Heights
- (Simcoe County) Mitchell Square
- (United Counties of Leeds and Grenville) Mitchellville