William de Deyn [de la Deyn] (died 1350) was a 14th-century Scottish monk and cleric. Little can be said about Deyn's early life. He had obtained alicentiate indecrees at some point in his youth, and he must have become aTironensian monk, for by 1329, and perhaps as early as 1327, he wasAbbot of Kilwinning.Kilwinning Abbey was a Tironensian house inCunninghame, in existence since the 1160s. He appears for the first time in this capacity as witness to acharter of Walter Comyn of Rowallan.

In 1344, Deyn, perhaps through Stewart patronage, was chosen to succeedAlexander de Kininmund asBishop of Aberdeen. Deyn travelled tocontinental Europe, and by 27 September had receivedconsecration. His consecration had been performed by Cardinal Peter Despres. In May 1345, the Pope appointed him as Scotland's papal tax collector, a duty Deyn fulfilled, sending the proceeds to the papacy via merchants inBruges. He was one of the notables who petitioned the papacy in 1347 to legitimise the marriage ofRobert Stewart and Elizabeth More of Rowallan. In 1349 he was in attendance with theJusticiar of Scotia holding court at thestanding stones ofOld Rayne inGarioch.^[1]

He died on 20 August 1350 and was buried in thechoir ofAberdeen Cathedral.

• 1350 deaths
• 14th-century Scottish Roman Catholic bishops
• Abbots of Kilwinning
• Bishops of Aberdeen
• Burials at St Machar's Cathedral
• 14th-century Christian abbots

• Articles with short description
• Short description is different from Wikidata
• Use dmy dates from January 2017
• Use British English from January 2017
• Year of birth unknown