John Dunstaple (or Dunstable; c. 1390 – 24 December 1453) was an English composer whose music helped inaugurate the transition from the medieval to the Renaissance periods.^[1] The central proponent of the Contenance angloise style (lit. 'English manner'), Dunstaple was the leading English composer of his time, and is often coupled with William Byrd and Henry Purcell as England's most important early music composers.^[2] His style would have an immense influence on the subsequent music of continental Europe, inspiring composers such as Du Fay, Binchois, Ockeghem and Busnois.^[2]

Information on Dunstaple's life is largely non-existent or speculative,^[3] with the only certain date of his activity being his death on Christmas Eve of 1453. Probably born in Dunstable in Bedfordshire during the late 14th-century, Dunstaple was associated with Humphrey, Duke of Gloucester and Joan of Navarre, and, through them, St Albans Abbey. Another important patron was John, Duke of Bedford, with whom Dunstaple may have travelled to France.

Dunstaple's surviving music is exclusively vocal, and frequently uses isorhythms, while pioneering the prominent use of harmonies with thirds and sixths.