Jeet Kune Do (Chinese: 截拳道; Cantonese Yale: jiht kyùhn douh; [tsìːt̚.kʰy̏ːn.tòu]), "The way of the intercepting fist" in Cantonese, abbreviated JKD, is a hybrid philosophy of martial arts heavily influenced by the personal philosophy and experiences of martial artist Bruce Lee. Lee, who founded the system on July 9, 1967, referred to it as "non-classical", suggesting that JKD is a form of Chinese Kung Fu, yet without form.

Unlike more traditional martial arts, It was named for the Wing Chun concept of interception or attacking when one's opponent is about to attack. Jeet Kune Do practitioners believe in minimal effort with maximum effect. On January 10, 1996, the Bruce Lee Foundation decided to use the name Jun Fan Jeet Kune Do ( 振藩截拳道) to refer to the martial arts system which Lee founded; "Jun Fan" being Lee's Chinese given name.

In the screenplay of the 1973 Warner Brothers film, Enter the Dragon, when Lee is asked, "What's your style?" Lee replied, "My style?...You can call it the art of fighting without fighting."

Bruce Lee believed that kata forms and martial art tournament matches alike (like Karate) were simply "organised despair". He believed that in order to "fully express oneself, one must "have no limitations" (kata and rigid and non-flowing movements being the limitation). His system was revolutionary, and included all possible forms of strikes: attacks to the groin, finger jab to the eye.

The name Jeet Kune Do was often said by Lee to be just a name, and he often referred to it as "the art of expressing the human body" in his writings and in interviews. Through his studies Lee came to believe that styles had become too rigid and unrealistic. He called martial art competitions of the day "dry land swimming". He believed real combat was spontaneous, and a martial artist cannot predict it, but only react to it, and a good martial artist should "be like water"—move fluidly without hesitation.