Castor of Karden was a 4th-century priest and hermit who lived in the regions of Aquitaine and Treis-Karden. A student of Maximinus of Trier, he was ordained by his teacher around 345 AD. Following his ordination, he moved to Karden on the Moselle to live an ascetic life. There, he founded a small religious community alongside several companions, including the pilgrim Saint Potentinus and his sons, Felicius and Simplicius.