M
- (Hastings County) Maynooth Station
- (Hastings County) McAlpine Corners
- (Lanark County) McCann's Shore
- (United Counties of Leeds and Grenville) McCarleys Corners
- (Thunder Bay District) McCluskeys Corners
- (Timiskaming District) McCool
- (Northumberland County) McCracken Landing
- (Peterborough County) McCrackens Landing
- (Hastings County) McCrae
- (Lanark County) McCreary's Shore
- (Lanark County) McCulloughs Landing
- (Lanark County) McDiarmid's Shore
- (Renfrew County) McDougall
- (Hastings County) McGary Flats
- (Huron County) McGaw
- (Rainy River District) McGinnis Creek
- (Renfrew County) McGrath
- (Lennox and Addington County) McGuire Settlement
- (Bruce County) McIntosh
- (United Counties of Leeds and Grenville) McIntosh Mills
- (Lennox and Addington County) McIntyre
- (Grey County) McIntyre
- (Ottawa) McKay's Waterfront
- (Ottawa) McKellar Heights
- (Nipissing District) McKenzie Lake
- (Durham) McLaren's Beach
- (Renfrew County) McLarens Settlement
- (Frontenac County) McLean
- (United Counties of Leeds and Grenville) McLeanville
- (Durham) McLennan's Beach