Ero of Armenteira was a 12th-century abbot from the O Salnés region of Galicia. Originally a knight living near Mount Castrove, he and his wife, unable to have children, chose to pursue a spiritual life instead. This decision led him to establish the monastery of Santa María de Armenteira with the assistance of monks sent by Saint Bernard of Clairvaux. He eventually served as the monastery's abbot and is remembered for a legendary experience involving a divine vision.