Lieutenant-Colonel Sir Rhys Llewellyn, 2nd Baronet, CStJ (9 March 1910 – 25 April 1978) was a Welsh mining executive, soldier, author and dignitary. He was born in Aberdare, South Wales, the son of a colliery owner. Educated at Oundle School and Trinity College, Cambridge he was the Managing Director of Graigola Merthyr from 1934 to 1947; Master of the Brecon and Talybont Foxhounds from 1936 to 1940; an officer in the Welsh Guards during World War II; and High Sheriff of Glamorgan from 1950 to 1951.