Aibert of Crespin was a 12th-century Benedictine monk and hermit who lived in the Diocese of Tournai. Born in 1060 to a knight, he initially pursued a life of extreme asceticism under the guidance of a hermit named John. After traveling to Rome, he joined Crespin Abbey, where he served as both provost and cellarer for twenty-five years. Later in life, he returned to a solitary existence in the wilderness, where he served as a priest and provided spiritual guidance to those who sought him out.