CMJ (disambiguation)
CMJ was a music events/online media company which hosted an annual festival in New York City
CMJ may also refer to:
- Central Motorway Junction, motorway interchange in Auckland, New Zealand
 - Christopher Martin-Jenkins (1945–2013), English cricket journalist and broadcaster
 - Church's Ministry Among Jewish People, an Anglican church organisation
 - CMJ University, Chandra Mohan Jha University, India
 - College Mathematics Journal, a journal of the Mathematical Association of America
 - Computer Music Journal, quarterly academic journal covering digital audio signal processing and electroacoustic music
 - The Cormac McCarthy Journal, an academic journal dedicated to the works of American author Cormac McCarthy
 - Qimei Airport (IATA airport code), Cimei, Penghu, Taiwan
 - CMJ ammo, full metal jacket ammunition with cupronickel jacket