Joseph Hahn, also known as Joe Hahn, and also known by his stage name Mr. Hahn (born March 15, 1977, Dallas, Texas, USA) is an American turntablist and director best known as the DJ and sampler for the American rock band Linkin Park. Hahn is a second generation Korean American.

Hahn began deejaying in high school, and he studied illustration at the Art Center College of Design in Pasadena, California. In college, he met Mike Shinoda, and joined his band Xero, which later became known as Linkin Park.

Hahn was called Chairman Hahn on the back cover of Linkin Park’s Remix album Reanimation next to the songs With You and Cure For The Itch. Hahn has directed several of Linkin Park’s music videos, such as those for Numb, From the Inside, What I’ve Done, Somewhere I Belong, Pts.OF.Athrty, New Divide, Bleed it Out and Iridescent.
He has also directed videos for Story of the Year, Xzibit, and Alkaline Trio.

Outside of his work in music, Hahn provided special effects work on The X-Files and the miniseries Frank Herbert’s Dune.

Hahn directed the trailer for the video game Medal of Honor, featuring Linkin Park’s single The Catalyst.

Hahn became the first Korean American to receive a Grammy when the band won the 2002 award for Best Hard Rock Performance.