The Mask of Orpheus is an opera with music by Harrison Birtwistle, electronic music realised by Barry Anderson and a libretto by Peter Zinovieff. It was premiered in London at the English National Opera on 21 May 1986 to great critical acclaim. A recorded version conducted by Andrew Davis and Martyn Brabbins has also received good reviews. A new production of the opera was staged at the English National Opera in 2019, conducted by Martyn Brabbins and James Henshaw. The work is around three hours long.

Sir Harrison Birtwistle was an English composer of contemporary classical music best known for his operas, often based on mythological subjects. Among his many compositions, his better known works include The Triumph of Time (1972) and the operas The Mask of Orpheus (1986), Gawain (1991), and The Minotaur (2008). The last of these was ranked by music critics at The Guardian in 2019 as the third-best piece of the 21st century. Even his compositions that were not written for the stage often showed a theatrical approach. A performance of his saxophone concerto Panic during the BBC's Last Night of the Proms caused "national notoriety". He received many international awards and honorary degrees.