Every Good Boy Deserves Favour is a stage play by Tom Stoppard. It was first performed in 1977.

The play was written at the request of André Previn and was inspired by a meeting with Russian exile Viktor Fainberg . The play calls for a small cast, but also a full orchestra, which not only provides music throughout the play (composed by Previn) but also forms an essential part of the action. The play concerns a dissident under an oppressive regime (obviously meant to be taken for a Soviet controlled state) who is imprisoned in a mental hospital, from which he will not be released until he admits that his statements against the government were caused by a (non-existent) mental disorder.

The title derives from the popular mnemonic used by music students to remember the notes on the lines of the Treble clef

Every Good Boy Deserves Favour is also the title of an album by The Moody Blues.