Rhodri ap Hyfaidd (died 905) was briefly the king of Dyfed in southwestern Wales. After his brother Llywarch was killed by Hywel Dda and his father Cadell, Rhodri briefly reigned before he himself was killed and the throne was usurped by Hywel, under whom the kingdom then merged with Seisyllwg to form Deheubarth.^[1]