Gun Jack

refers to multiple fictional characters in the game Tekken. The character is an android, first introduced under the name "Jack" in the original video game Tekken. Subsequent Tekken games feature an upgraded model with a slightly different name, with the exception of Tekken 4, in which he makes no appearance.

The various Jack models were originally created by the Mishima Zaibatsu and G Corporation for different purposes:

The Jack series robots also appear in Tekken Tag Tournament (Jack-2, Gun Jack, and Prototype Jack) and Tekken Tag Tournament 2 (Jack-6 and Prototype Jack).

In-game, the Jacks have traditionally shared a number of their moves with Kuma/Panda and Ganryu. In Tekken 5, however, Namco made a pronounced effort to differentiate all the shared moves between characters: the fighters still have a few similar moves, but their executions are completely different. In Tekken 5, Jack-5 is considered one of the most difficult characters to play. Inversely, in Tekken 6, Jack-6 is considered one of the easiest characters to learn.