| ISTAR | Indiana Standard Tool For Alternate Reporting 
| Others |
| ISTAR | Indiana Standards Tool For Alternate Reporting
| Others |
| ISTAR | Indiana Student Teacher Achievement Recognition
| Others |
| ISTAR | Information Society Training and Awareness Raising
| Others |
| ISTAR | Institute for Strategic Threat Analysis and Response
| Others |
| ISTAR | Intelligence, Surveillance, Target Acquisition, and Reconnaissance
| Military, Defence |