"Lone Jack" is an instrumental jazz fusion piece composed by Lyle Mays and Pat Metheny, who are credited as its composers on the album credits. It first appeared on the self-titled debut album of the Pat Metheny Group, released by ECM in March 1978 as catalogue number ECM 1114. The track is the fourth on side B and runs about 6:41. Its style is classified as fusion within jazz, and it is performed without sung lyrics.
A recording by the group is dated 1977, earlier than the album's release. Among later versions, the Pat Metheny Trio performed the piece in 2000.
