Ardo Smaragdus was a 9th-century Benedictine monk and hagiographer who lived in Aniane. Raised within the monastery by Benedict of Aniane, he eventually rose to become a priest and the leader of the monastery school. Following the departure of his mentor to the imperial court in 814, Smaragdus assumed the role of abbot. He is recognized as a saint in several Christian traditions, including the Catholic, Anglican, and Orthodox churches.