John of Jesus Hernández y Delgado was a 17th-century Spanish Franciscan friar and mystic from Tenerife. Born in December 1615, he spent his early years working as a cooper, during which time he suffered a severe injury to his left eye caused by a violent employer. After years of supporting his mother, he joined the Order of Friars Minor in 1646. He became well known for his intense penitential lifestyle, his spiritual guidance, and his frequent mystical experiences, which earned him both devotion and occasional hostility from his peers.