- Stittsville
- Stoco
- Stonecliffe
- Stones Corners
- Stonyridge
- Stonywood
- Storie
- Storms Corners
- Strange
- Stratford
- Strathallan
- Strathavon
- Strathburn
- Strathcona
- Strathroy
- Strickland
- Strong
- Strongville
- Sulphide
- Sulphur Island
- Summer Beaver
- Summerhill
- Summers Corners
- Sunbury
- Sunderland
- Sundridge
- Sunnidale
- Sunnidale Corners
- Sunny Slope
- Sunrise Beach