Jaden Yuki, known as Judai Yuki in the original Japanese version, is a fictional character and the main protagonist of the Yu-Gi-Oh! GX anime and mangaseries. His name is meant to be a pun in Japanese, as "jūdai" is the word for "teenager". In the English version, Jaden is voiced by Matthew Charles, while KENN (older) and Mariko Nagahama (younger) take the role in the Japanese version.

In the anime, he is a teenager who attends Duel Academy, a school teaching the fictional game of Duel Monsters founded by Seto Kaiba of the original anime. He is placed in Slifer Red dormitory (the lowest ranking), but during the series he is chosen as one of Duel Academy's best duelists. He later gains the Neo-Spacian and Elemental Hero Neos cards, which become his signature monsters. In the third series, Jaden discovers that his childhood favourite card, Yubel, has turned evil and is being cured by a guest teacher, Professor Viper. Yubel transports Duel Academy to an alternate dimension, where Jaden becomes an evil spirit called the Supreme King. Once healed, he gains the powers of Yubel and the Supreme King.