"Friend of the Devil" is a song by the Grateful Dead and recorded as the second track of the Dead's 1970 album American Beauty. The music was written by Jerry Garcia and John Dawson and the lyrics are by Robert Hunter. Like most of American Beauty, the song is largely acoustic. It opens with Garcia playing a descending G major scale (G F# E D C B A G) in the bass register.

The song follows an unnamed person on the run from his wives, a sheriff, twenty hounds, and the Devil. His journey begins in Reno, Nevada, there are mentions of wives in the California towns of Chino and Cherokee, and spending a night in a cave in Utah, as the person attempts to return home to rest. In the end, their fate remains unresolved.

The song was introduced in concert on March 20, 1970, at the Capitol Theatre in Port Chester, New York.

Following the group's October 1974–June 1976 touring hiatus, the song was performed in a significantly slower arrangement with extended guitar and keyboard solos. In more recent history, Phil Lesh and Friends have performed a more uptempo version similar to the original.^{[citation needed]}

Hunter plays a slightly different version on his album (released only in LP format) Jack O'Roses. He adds a final verse:

"You can borrow from the Devil/ You can borrow from a friend/ But the Devil'll give you twenty/ When your friend got only ten"