(17 October 1253 – 19 May 1303), also known Yvo or Ives (and in Breton as Erwan, Iwan, Youenn or Eozenn, depending on the region, and known as Yves Hélory (also "Helori" or "Heloury") in French), was a parish priest among the poor of Louannec, the only one of his station to be canonized in the Middle Ages.