| Isle Of Wight County, VA (County) |
| Isles of Bartram Park Community Development District, FL (CDD) |
| Islesboro, ME (Town) |
| Isleton, CA (City) |
| Isley, ND (Township) |
| Islip, NY (Town) |
| Ismay, MT (Town) |
| Isola, MS (Town) |
| Israel Township, OH (Township) |
| Issaquah, WA (City) |
| Issaquena County, MS (County) |
| Italy, NY (Town) |
| Italy, TX (Town) |
| Itasca, TX (City) |
| Itasca, KS (Township) |
