Jeff (Japanese:ジェフ) is a fictional character in the video game EarthBound and is one of the four main characters.

Jeff is from the Snow Wood Boarding School in Winters. He is the only member of the four that cannot use PSI power, but he has two advantages that the other characters don't have: Jeff can repair broken items and use them as weapons if his IQ stat is high enough, and he can spy on enemies to find out their stats. However since his weapons are guns, the player will not find himself getting SMAAASH! hits (Earthbound's equivalent of a "critical hit") using Jeff often. His speed is somewhat low, but still higher than Ness's, and he has more defense than Ness and Paula have.

Jeff is the only character that uses the most powerful weapon in the game: the Multi-Bottle rocket. Some veterans argue that this item makes the game too easy once obtained, despite the fact that one boss in the game can actually turn its power against Jeff.

A trophy of Jeff can be obtained in Super Smash Bros. Melee.