Aelred of Rievaulx (Latin: Aelredus Riaevallensis); also Ailred, Ælred, and Æthelred; (1110 – 12 January 1167) was an English Cistercian monk, abbot of Rievaulx from 1147 until his death, and known as a writer. He is regarded by Anglicans, Catholics, and other Christians as a saint.
Aelred was born in Hexham, Northumbria, in 1110, one of three sons of Eilaf, priest of St Andrew's at Hexham, himself a son of another Eilaf, treasurer of Durham.
Aelred spent several years at the court of King David I of Scotland in Roxburgh, possibly from the age of 14, rising to the rank of echonomus (often translated "steward" or "Master of the Household") before leaving the court at age twenty-four (in 1134) to enter the Cistercian abbey of Rievaulx in Yorkshire. He may have been partially educated by Lawrence of Durham, who sent him a hagiography of Saint Brigid.
From 1142 – 1143, Aelred served as novice master at Rievaulx. of a new daughter house of Rievaulx at Revesby in Lincolnshire. In 1147, he was elected abbot of Rievaulx itself, a position he was to hold until his death. Under his administration, the abbey is said to have grown to some 140 monks and 500 conversi and laymen.