| Sisseton, SD (Township) |
| Sisseton, SD (City) |
| Sisseton, SD (Township) |
| Sister Bay, WI (Village) |
| Sisters, OR (City) |
| Sistersville, WV (City) |
| Sitka, AK (City) |
| Sitka Township, KS (Township) |
| Sitka Borough, AK (County) |
| Six Mile, SC (Town) |
| Six Mile Creek Community Development District, FL (CDD) |
| Six Mile Grove, MN (Township) |
| Six Mile Township, IL (Township) |
| Skagen, MN (Township) |
| Skagit County, WA (County) |
