- Sheridan
- Sheridan Trailer Court
- Sherryl
- Shields
- Shields Crossing
- Shigley Mobile Home Park
- Shirley
- Shonkin
- Shonkin Bar
- Sidney
- Siebeck Island
- Sieben
- Silesia
- Silver Bow
- Silver Bow Park
- Silver City
- Silver Gate
- Silver Star
- Simko Trailer Court
- Simms
- Simpkins Place
- Simpson
- Singleshot
- Sioux Crossing
- Sioux Pass
- Sipes
- Sipple
- Sixmile Crossing
- Sixteen
- Siyeh Bend