Saint Yban, also known as Saint Ethbin, saint Iboan, saint Diboan, saint Diboen, saint Iben, saint Ibe, saint Abibon, saint Languis, saint Langui, saint Idunet, saint Ivinec, is one of a number of semi-legendary Breton saints from Armorica who are recognized by the Catholic Church. He was a disciple of Saint Winwaloe. He founded a priory which is today the city of Châteaulin.