S
- (Algoma) Sault Ship Canal
- (Simcoe County) Saurin
- (Regional Municipality of Waterloo) Schindelsteddle
- (Simcoe County) Schomberg Heights
- (Thunder Bay District) Schreiber
- (Renfrew County) Schutt
- (Perth County) Science Hill
- (Thunder Bay District) Scoble West
- (Manitoulin District) Scotch Block
- (Hastings County) Scotch Bush
- (Renfrew County) Scotch Bush
- (Lanark County) Scotch Corners
- (Lanark County) Scotch Line
- (United Counties of Leeds and Grenville) Scotch Point
- (Frontenac County) Scotch Settlement
- (Parry Sound District) Scotia
- (Hastings County) Scott Settlement
- (Peterborough County) Scott Settlement
- (Peterborough County) Scotts Landing
- (Essex County) Scudder
- (Durham) Scugog
- (Durham) Scugog Centre
- (Durham) Scugog Point
- (District Municipality of Muskoka) Sea Breeze
- (Perth County) Sebastopol
- (Perth County) Sebringville
- (Lambton County) Seckerton
- (United Counties of Leeds and Grenville) Seeley
- (Parry Sound District) Seguin Falls
- (Thunder Bay District) Sellars