Hywel Coetmor was a Welsh knight who took part in Owain Glyndŵr's rebellion. His brother was Rhys Gethin, who was one of Glyndŵr's leading generals.[1] He had earlier fought under the Black Prince at the Battle of Poitiers (1356).
He married Gwenllian, a daughter of Rhys ap Robert (d. 1377), a prominent nobleman who had supported Owain Lawgoch. An effigy of him can be seen in St Grwst's Church at Llanrwst.