He was born on 30 June 1900, the son of James Jones and Elizabeth Bowyer and was brought up in the Welsh community of Rhos. He was a brother to Thomas William Jones MP, Baron Maelor (1898—1984). He was educated at Ruabon Grammar School and Bangor Normal College. He later gained the degree of B.Sc.(Econ) as an external student of the University of London in 1936. He began his career as a certified schoolteacher in 1922 and was headmaster of Grange Secondary Modern School, Rhosllanerchrugog, from 1938 until 1954. He became a non—professional pastor with the Scotch Baptists in Wales in 1924. Jones joined the ILP as a young man. He contested the Denbigh division as a Labour candidate in the general election of 1951, and then captured Wrexham in a by—election held in March 1955 following the death of Robert Richards MP. He continued to represent Wrexham until his retirement from parliament in June 1970. He was chairman of the Welsh Parliamentary Party, 1957—58, and of the Welsh Labour Group, 1960—61. In 1965 he also served as a member of the Commons Group Reviewing Electoral Law and Procedure. During his parliamentary career he was instrumental in securing many new industries for the Wrexham area to replace those, such as coal, which were very much on the decline. He won the respect and friendship of political opponents.
Jones published a number of volumes in both Welsh and English on the history and geography of Wales. His many publications include A Geography of Wales (1938), An Atlas of Denbighshire (1950), Atlas Hanesyddol Cymru (1952, new edition 1972), A Geographical Atlas of Wales (1955), A Historical Atlas of Wales (1955), A New Geography of Wales (1960) and J. R. Jones (Ramoth) a'i Amserau (1967). His hobbies were photography and landscape painting. He was a member of the Gorsedd of Bards. His papers are in the custody of the Denbighshire Record Office, Ruthin. Jones had married in 1931 Catherine Humphreys, and they had three children. One daughter predeceased her father. They lived at Ellis Street, Maelor, Ponciau, Wrexham. He died, after a very long illness, on 18 October 1982. He was buried in Rhos cemetery.