| Simpsonville, KY (City) |
| Sims, IN (Township) |
| Sims, NC (Town) |
| Sims, IL (Village) |
| Sims Township, MI (Township) |
| Simsboro, LA (Village) |
| Simsbury, CT (Town) |
| Sinai, SD (Town) |
| Sinclair, KS (Township) |
| Sinclair, ND (Township) |
| Sinclair, WY (Town) |
| Sinclair, MN (Township) |
| Sinclairville, NY (Village) |
| Sinking Spring, PA (Borough) |
| Sinking Spring, OH (Village) |
