Deer Abbey was a Cistercian monastery in Buchan, Scotland. It was founded by 1219 AD with the patronage William Comyn, jure uxoris Earl of Buchan, who is also buried there. There was an earlier community of Scottish monks or priests. The notitiae on the margins of the Book of Deer record grants made to the Scottish religious community in the 12th century and a claim that it was founded by Saint Columba and Saint Drostan. The old religious community was probably absorbed by the new foundation. The history of the abbey after the 1210s is obscure until the 16th century, when it was beginning to be secularized.