| Acronym | Definition |
|---|
| IRST | Intel Rapid Storage Technology (Intel Corp.) |
| IRST | Infrared Search and Track (US DoD) |
| IRST | Iran Standard Time (time zone) |
| IRST | Istituto per la Ricerca Scientifica e Tecnologica (Centre for Scientific and Technological Research, Istituto Trentino di Cultura, Trento, Italia) |
| IRST | Institute for Scientific and Technological Research |
| IRST | Ionospheric Radio Systems and Techniques (conference) |
| IRST | Incident Response and Security Team |
| IRST | Immediate Response Spill Technologies, LLC (Louisville, KY) |