- Smelter Heights
- Smelterville
- Smith Corrals
- Smith Island
- Smith Springs
- Smiths Ferry
- Smiths Island
- Snells Island
- Snyders
- Soda Springs
- Soldier
- Sonna
- South Mountain
- Southwick
- Spalding
- Sparlin Island
- Spencer
- Spink
- Spirit Lake
- Spiry Place
- Split Island
- Spring Island
- Springdale
- Springfield
- Springston
- Squirrel
- Staffel Island
- Staley Springs
- Stanford
- Stanley