John Peckham (c. 1230 – 8 December 1292) was a Franciscan friar and Archbishop of Canterbury in the years 1279–1292.
Peckham studied at the University of Paris under Bonaventure, where he later taught theology and became known as a conservative opponent of Thomas Aquinas, especially regarding the nature of the soul. Peckham also studied optics and astronomy - his studies in those subjects were particularly influenced by Roger Bacon and Alhazen. Around 1270, Peckham returned to England, where he taught at the University of Oxford, and was elected the Franciscans provincial minister of England in 1275. After a brief stint in Rome, he was appointed Archbishop of Canterbury in 1279. His time as archbishop was marked by efforts to improve discipline in the clergy as well as reorganize the estates of his see. He served King Edward I of England in Wales.
Before and during his time as archbishop, he wrote a number of works on optics, philosophy, and theology, as well as writing hymns.