Hywel ap Edwin (died 1044) was king of Deheubarth in south Wales from 1033 to 1043.
Hywel and Maredudd's rule did not go unchallenged as the sons of Rhydderch fought in a battle against them in 1034 at Irathwy.
Though sources do not name the victors it seems as though Hywel and Maredudd were victorious as they remained in power.
He came under increasing pressure from Viking raids and from Gruffydd ap Llywelyn who had already seized the throne of Gwynedd.
He returned in 1044 with the aid of an Irish fleet to try to regain his kingdom, but Gruffydd defeated them in a battle near the mouth of the River Towy, in which Hywel was killed.