| Abbreviation | Definition |
|---|---|
| ISD | Iscuande, Colombia |
| ISE | Isparta, Turkey |
| ISG | Ishigaki, Japan |
| ISH | Ischia, Italy |
| ISI | Isisford Airport, Isisford, Queensland, Australia |
| ISJ | Isla Mujeres, Mexico |
| ISK | Nasik, India |
| ISL | Isabel Pass Airport, Isabel Pass, Alaska USA |
| ISN | Williston, North Dakota USA |
| ISO | Kinston, North Carolina USA |
| ISP | Long Island MacArthur Airport, Long Island, New York USA |
| IST | Istanbul, Turkey |
| ISW | Wisconsin Rapids, Wisconsin USA |
| ITB | Itaituba, Paranaibo, Brazil |
| ITE | Itubera, BA, Brazil |
| ITH | Ithaca, New York USA |
| ITI | Itambacuri, Minas Gerais, Brazil |
| ITK | Itokama, Papua New Guinea |
| ITM | Itami, Japan |
| ITO | Hilo, Hawaii USA |