HJ

HJ or Hj can mean:

* Asian Express Airlines IATA airline designator
* Handjob, a sexual act
* hectojoule (hJ), an SI unit of energy equal to 10² joules
* Hall–Janko group, a mathematical group
* Hero's Journey (MMORPG), the game by Simutronics Corp.
* Heterojunction, the interface between two layers of dissimilar crystalline semiconductors
* Hilal-i-Jurat, the second highest military award of Pakistan
* Hitler-Jugend, the German name for the Hitler Youth
* Hotel juliet, U.S. code word for a cryptographic key change