He was born on 29 June 1904, the son of Evan Ungoed-Thomas, minister of Tabernacle Welsh Baptist Church,
Carmarthen, for more than forty years. He was educated at
Queen Elizabeth Grammar School (Carmarthen),
Haileybury College and
Magdalen College, Oxford. He married on 19 April 1933 to Dorothy, the daughter of Jasper Travers Wolfe of county Cork. They had two sons and one daughter. Ungoed-Thomas played
rugby union for
Leicester Tigers in 1931, featuring in eight games between January and March and scoring two tries. == Career ==