Gruffydd ab Owain (died) was a joint king of Glywysing in Wales along with his brother Cadwgan.[1] His other brother Morgan ruled in Gwent.
His death was recorded in the Annals of Wales.[2] Phillimore's reconstruction of the dates places the entry in AD 935.[3] Afterwards, his brother Cadwgan seems to have ruled Glywysing alone until his death .