The Bayreuth Festival Orchestra is a seasonal German orchestra based at the Bayreuth Festspielhaus for the annual summer festival Bayreuth Festival. It is reconstituted each season in order to perform Richard Wagner's Der Ring des Nibelungen and other of his stage works, as envisaged by the composer and festival founder. The festival occurs annually, although in some years it was cancelled because of war or other reasons.

Although otherwise entirely devoted to the works of Wagner, the inaugural festival in 1876 was opened with a performance of Beethoven's Choral Symphony, and this practice has often been followed subsequently. It has become something of a tradition since Wilhelm Furtwängler reintroduced it in the 1930s.

The Bayreuth Festival Orchestra does not have a permanent membership but each year the festival organisers recruit leading musicians from other German orchestras, depending on their availability. Some musicians always arrange their schedules so as to be available for the orchestra; others participate less frequently.