| Abbreviation | Definition |
|---|---|
| ISIS | Interchangeable/Substitutability Information System |
| ISIS | Interchangeablity/Substitutability Information System |
| ISIS | Islamic State in Iraq and Syria |
| ISIS | Islamic State of Iraq and Syria |
| ISIS-K | Islamic State in Iraq and the Levant - Khorasan Province |
| ISL | Islamic State in Lanao |
| ISM | Imperial Service Medal |
| ISM | Installation Support Module |
| ISM | Integrated Sustainment Maintenance |
| ISM | International Safety Management |
| ISMA | Information Systems Management Activity |
| ISMCS | International Station Meteorological Climatic Summary |
| ISMMP | Integrated Continental United States (CONUS) Medical Mobilization Plan |
| ISMP | Information Standards Management Panel |
| ISMP | Integrated Safety Management Plan |
| ISN | Bureau of International Security and Nonproliferation |
| ISN | Internal Serial Number |
| ISN | Internment Serial Number |
| ISNS | Integrated Shipboard Network System |
| ISO | In Support Of .... |