Tomas ap Rhodri ab Owain Gwynedd was the only known son of Rhodri ab Owain Gwynedd ruler of half Gwynedd from 1170–1195. In the 17th century, Sir John Wynn, 1st Baronet of Gwydir claimed and later proved his ancestor was Tomas ap Rhodri, however the Wynn family expired in the male line by the middle of the 18th century. A surviving line of male line descendants of Tomas ap Rhodri are the Anwyl of Tywyn Family.