Ailerán, also referred to as Ailerán the Wise, was a prominent 7th-century Irish scholar and saint. He served as a lector at the School of Clonard, drawn there by the reputation of Saint Finnián. Recognized for his deep understanding of patristic literature, he studied the writings of figures such as Augustine and Jerome. His life ended during the outbreak of the Yellow Plague, an event documented in the Annals of Ulster.