- Seneca
- Sepo
- Serena
- Sesser
- Seville
- Seward
- Sexson Corner
- Seymour
- Shabbona
- Shabbona Grove
- Shadow Lawn
- Shady Acres
- Shady Beach
- Shady Grove
- Shady Hollow
- Shafter
- Shakerag
- Shale Bluff
- Shale City
- Shamrock
- Shamrock
- Shandrew Island
- Shanghai City
- Shannon
- Sharpsburg
- Shattuc
- Shaw
- Shawneetown
- Shaws
- Sheehan Island