Almost nothing is known about his life, except that he died on Christmas eve 1453, as this was mentioned in his epitaph. He is widely held to have been at the service of the duke of Bedford, the brother of Henry V. As such he may have stayed in France for some time, since the duke was regent of France and governor of Normandy from 1423 to 1429 and from 1429 to 1435 respectively.
Dunstable was one of the first to compose masses using a single melody as cantus firmus. A good example of this technique is his Missa Rex Seculorum.
Copies of his works have been found in continental manuscripts, which suggests that his fame was widespread. He was praised by the French poet Martin Le Franc, who wrote that his contenance angloise ("English guise") influenced Dufay and Binchois.
Of the works attributed to him about 50 survive, among which two complete masses, several individual mass sections, isorythmic motets (among which the famous one which combines the hymn Veni Creator Spiritus and the sequence Veni Sancte Spiritus), as well as settings of various liturgical texts.
Although he is believed to have written secular music, no songs in vernacular can be attributed to him with any degree of certainty. The popular melody O rosa bella, once thought to be by Dunstable, is now attributed to John Bedyngham.