GJ or Gj may refer to:
Science and technology Gigajoule (GJ), a unit of energy Gastrojejunal feeding tube, in medicine Gliese–Jahreiß Catalogue, in star designators
Transport codes Gujarat, the Indian state in vehicle registrations Eurofly, an Italian airline (by defunct IATA code) Mexicargo, a Mexican airline (defunct IATA code) Loong Air, a Chinese airline (IATA code)
Other uses Gj (letter), a Latin digraph Gebirgsjäger, alpine light infantry of Austria and Germany Gharjamai, a live-in son-in-Law Gilets jaunes (yellow vests) movement, grassroots political movement in France "GJ!", a song by Babymetal on the 2016 album Metal Resistance An acronym for Geometry Jump, the old name of the video-game Geometry Dash
See also Good job (disambiguation)