Tewin is known to have been settled by the Angles in 449 AD; the name being a derivative of the Old English words for the Norse god Týr (“Tiw”) and meadow (“Ing”). However the name varies over the centuries – in the "Domesday Book" it is Tewinge and Theinge – and in the 16th century Tewinge, Tewing and Twying, but it is thought the village became Tewin in the 18th century. An alternative derivation from Britonnic is possible, connected with the modern Welsh "Tywyn" or Dune.