IRT may refer to:

Science and technology

* Imagery rehearsal therapy, a treatment for nightmare disorders * Immunoreactive trypsinogen, newborn screening test for cystic fibrosis * Infrared thermography * Infrared Telescope (IRT), carried on Space Shuttle mission STS-51-F * Item response theory, to interpret psychometric tests

Television

* '' Ice Road Truckers'', a reality television series * International Response Team, a fictional body in ''Criminal Minds''

* IR Tanger, a Moroccan association football club * Incident response team, a group of people who prepare for and respond to any emergency incident * Indiana Repertory Theatre, Indianapolis, US * Institut für Rundfunktechnik, a German research institute for broadcasters * Interborough Rapid Transit Company, former New York City Subway operator * '' International Registry of Tartans'', a textile database also known as ''TartanArt'' {{disambig