Sir Kahedin (variantly spelled Kahadin, Kahedrin, Kaherdin, Kehenis, Kehidius; possibly the Welsh character Kae Hir) is brother to Iseult of Brittany and the son of King Hoel of Brittany in Arthurian legend. The story of his affair with Brangaine, the handmaiden of Iseult of Ireland is significantly mentioned in the Tristan and Iseult legend.