Fantinus was a tenth-century Italian monk and hermit who lived approximately from 927 to 1000. Born in Calabria to parents named George and Vriena, he entered monastic life at thirteen and served as both a cook and a porter. He later lived as an ascetic hermit near Mount Mercurion, where he practiced extreme self-denial and spent his time copying manuscripts. Known as Fantinus the Younger to distinguish him from an earlier saint, he eventually traveled to Greece to preach following a divine instruction.