Jeffrey Scot Tweedy (born August 25, 1967 in Belleville, Illinois, United States) is an American songwriter, musician and leader of the band Wilco. Tweedy joined rockabilly band The Plebes with high school friend Jay Farrar in the early 1980s, but Tweedy's musical interests caused one of Farrar's brothers to quit. The Plebes changed their name to The Primitives in 1984, and subsequently to Uncle Tupelo. Uncle Tupelo garnered enough support to earn a record deal and to tour nationally. After releasing four albums, the band broke up in 1994 because of conflicts between Tweedy and Farrar.

In 1994, Tweedy formed Wilco with John Stirratt, Max Johnston, and Ken Coomer. Wilco has released eight albums and found commercial success with their albums Yankee Hotel Foxtrot, A Ghost Is Born, Sky Blue Sky and Wilco (The Album). The band also released two collaboration albums with Billy Bragg and one with The Minus 5. Jeff Tweedy has been the recipient of two Grammy Awards, including Best Alternative Album for A Ghost Is Born. Tweedy has also participated in a number of side groups including Golden Smog and Loose Fur, has released a book of poems, and has released a DVD of solo performances. He was originally influenced by punk and country music, but has recently reflected more experimental themes in his music.

Tweedy has been afflicted with migraine headaches since childhood. Treatment for the migraines led to a dependency on painkillers, for which he underwent successful rehab in 2004. Tweedy also has been open about the fact that he suffers from clinical depression and panic attacks.