Cynhaiarn

Saint Cynhaiarn (Cynhaern) was a Welsh saint of the 5th or 7th century, patron of the church of Saint Cynhaiarn at Ynyscynhaearn near Criccieth in Gwynedd. Little is known of his life.

He was a prince of the house of Powys, a descendant of Vortigern, son of Hygarfael ap Cyndrwyn of Caereinion and brother of Saints Aelhaiarn and Llwchaiarn (Llanllwchaiarn). He was a cousin and disciple of Saint Beuno, sponsored by Saint Cadfan. The only church known for certain to be dedicated to him is the church of Saint Cynhaiarn near Criccieth. His feast day is not known. He is honored as a saint of the undivided Church.