| Abbreviation | Definition |
|---|---|
| IRBM | Intermediate Resource Ballistic Missile |
| IRBM | Inter-Region Beer Missile |
| IRC | Initial Response Cell |
| IRC | International Red Cross |
| IRCCD | Infrared Charge Coupled Device |
| IRCCM | Infrared Counter Countermeasures |
| IRCM | Infrared Countermeasures |
| IRD&S | International Research, Development, and Standardization |
| IRDO | Individual Replacement Deployment Operations |
| IRDS | Infrared Detection Set |
| IRDSS | Infrared Defeating Smoke system |
| IREMBASS | Improved Remotely Monitored Battlefield Sensor System |
| IRF | Immediate Reaction Force |
| IRF | Immediate Reaction Forces |
| IRF | Incident Response Force |
| IRFNA | Inhibited Red Fuming Nitric Acid |
| IRFPA | Infrared Focal Plane Array |
| IRG | Iraq Republic Guard |
| IRGC | Iranian Revolutionary Guard Corps |
| IRGCN | Iranian Revolutionary Guard Corps Navy |