David Clowes Williams was born in Tarbach, Port Talbot, the son of John Ffoulkes Williams and his wife Elizabeth, née Thomas. He attended the University of Wales in Cardiff and the Welsh National School of Medicine, where he was influenced by the teaching of Professor Grey Turner. He qualified MB BCh from Glasgow in 1929 and became a Fellow of the College in 1944. He held appointments as demonstrator in anatomy at University College, London, honorary surgeon to Aberdare General Hospital and Merthyr General Hospital, before becoming consultant surgeon to the West Wales General Hospital at Carmarthen. He died in 1992.