Bark Psychosis are an English post-rock band/musical project from east London formed in 1986. They were one of the bands that Simon Reynolds cited when coining "post-rock" as a musical style in 1994, and are thus considered one of the key bands defining the genre. Graham Sutton is the leader and consistent core member of the group, which is currently a flexible project consisting of Sutton supported by an altering roster of guest musicians.

During its original incarnation, the group was a more conventional quartet: Graham Sutton, Daniel Gish, John Ling and Mark Simnett. This line-up recorded most of the early EPs and the seminal 1994 album Hex. Recent contributing guest members include experimental guitarist Colin Bradley (of Dual) and Talk Talk drummer Lee Harris.