IRM may refer to:
IERS Reference Meridian
Illinois Railway Museum
Illinois Reserve Militia, state defense force active during World War II
Bureau of Information Resource Management, responsible for information technology of the U.S. Department of State
Information Rights Management
Intermediate Restorative Material (Dentistry) Zinc oxide eugenol
L'Institut Royal Météorologique de Belgique
Interference reflection microscopy, a microscopy method used to image adherent cells
Internal Revenue Manual, an official compendium of internal guidelines for personnel of the United States Internal Revenue Service
International Review of Mission, a quarterly academic journal
International Roaming MIN assigned by IFAST
IRM (album), by Charlotte Gainsbourg
Iron Mountain Incorporated, a data storage company based in Boston, Massachusetts
ICAO designator for Mahan Air, an Iranian airline
Islamic Republic of Mauritania
Irish Republican Movement
