Joseph Hahn, often referred to as Mr. Hahn, (born March 15, 1977 in Glendale, California) is a turntablist and director of Korean descent best known as the DJ for the American band Linkin Park.

Joe joined Linkin Park, after meeting fellow band mate Mike Shinoda in art school, when the band was called Xero in 1996 as the band's turntablist. Since then, he has directed music videos for most singles of his band, with the exceptions of "One Step Closer", "Crawling", "Faint" and "Given Up". He is referenced to as Mr. Hahn at the beginning of "Cure for the Itch" from Hybrid Theory as well as in "And One" from Hybrid Theory EP and "Kyur4 TH Ich" from Reanimation. He has also remixed their song "With You" (originally on "Hybrid Theory"), which appears on the remix album Reanimation as "Wth>You".

On the new album Minutes to Midnight, Joe Hahn focused his contributions on programming with his sound effects board and MIDI keyboard. Minutes To Midnight also features his turntable talents on three tracks: "What I've Done", "Valentine's Day", and "In Pieces." Joe has been known to utilize MIDI pads on several tracks from the band. Examples include "Crawling", "Numb", and "By Myself".