John Italus or Italos (Greek: Ἰωάννης ὁ Ἰταλός, Iōannēs o Italós; Latin: Johannes Italus) was a Neoplatonic Byzantine philosopher of the eleventh century. He was Calabrian in origin, his father being a soldier. He came to Constantinople, where he became a student of Michael Psellus in classical Greek philosophy. He succeeded Psellus in his position as head of the philosophical school. Subsequently he came into conflict with Diogenes, and he was condemned in 1082 by Patriarch Cosmas I of Constantinople for heresy.