| Name | What | Region | Country | Lat | Long | Elev Ft. | Pop Est |
| Iglesia | city | Puerto Rico | United States | 18.43139 | -67.15417 | 301 | 58726 |
| Iglesia Virgen de la Providencia | city | Puerto Rico | United States | 18.25028 | -66.19444 | 1797 | 116701 |
| Imbery | city | Puerto Rico | United States | 18.43889 | -66.55278 | 26 | 46048 |
| Indiera Alta | city | Puerto Rico | United States | 18.15361 | -66.885 | 2742 | 25697 |
| Indios | city | Puerto Rico | United States | 17.99611 | -66.81972 | 13 | 18774 |
| Ingenio | city | Puerto Rico | United States | 18.44417 | -66.22639 | 13 | 132215 |
| Isabel Josefa | city | Puerto Rico | United States | 18.10639 | -67.12694 | 45 | 37563 |
| Isabel Segunda | city | Puerto Rico | United States | 18.15111 | -65.44306 | 131 | 4376 |
| Isabela | city | Puerto Rico | United States | 18.50278 | -67.02472 | 200 | 16738 |
| Isidra | city | Puerto Rico | United States | 18.34111 | -65.64222 | 6 | 28154 |
| Isleta | city | Puerto Rico | United States | 18.37556 | -67.10889 | 328 | 54667 |
| Islote | city | Puerto Rico | United States | 18.48917 | -66.59722 | 0 | 29142 |
|
|