ZJ

ZJ or zJ may refer to:

Places

 * Zhejiang, a province of China

Science and mathematics

 * Zeptojoule (zJ), a small SI unit of energy
 * Zettajoule (ZJ), a large SI unit of energy
 * ZJ theorem, 1968, in group theory

Transport

 * Jeep Grand Cherokee (ZJ), 1993 models of the sports utility vehicle
 * Zambezi Airlines (2008–2012; IATA: )