S
- (Frontenac County) Snow Road Station
- (Manitoulin District) Snowville
- (Parry Sound District) Snug Harbour
- (Parry Sound District) Snug Haven
- (Durham) Solina
- (United Counties of Leeds and Grenville) Soperton
- (United Counties of Leeds and Grenville) South Augusta
- (District Municipality of Muskoka) South Bay
- (Peterborough County) South Beach
- (United Counties of Leeds and Grenville) South Branch
- (Peterborough County) South Dummer
- (Perth County) South Easthope
- (Middlesex County) Southgate
- (Thunder Bay District) South Gillies
- (United Counties of Leeds and Grenville) South Gower
- (Ottawa) South Keys
- (Parry Sound District) South Magnetawan
- (Ottawa) South March
- (Simcoe County) Southview Beach
- (Simcoe County) Southview Cove
- (Haliburton County) South Wilberforce
- (Elgin County) Southwold
- (Algoma) Sowerby
- (Frontenac County) Spaffordton
- (United Counties of Leeds and Grenville) Sparkle City
- (Elgin County) Sparta
- (Wellington County) Speedside
- (Parry Sound District) Spence
- (United Counties of Leeds and Grenville) Spencerville
- (Wellington County) Spier