He was born in Rhosllannerchrugog, Wrexham, and educated at Ruabon Grammar School and Normal College, Bangor. He became a teacher in 1922 in Holt, but then moved to positions in Glyn Ceiriog and Penycae. In 1938, he was appointed as headmaster at Grango School in his home village of Rhosllannerchrugog.
He first stood as a Labour Parliamentary candidate in 1951 for the Denbigh constituency, but was unsuccessful. He was elected at a by-election in March 1955 following the death of the sitting Labour MP Robert Richards. Jones held the seat at the general election in May 1955, and at subsequent elections until he retired from the House of Commons at the 1970 general election.
He died at Ponciau, Wrexham, aged 82.
- "JONES, JAMES IDWAL (1900-1982), headteacher and Labour politician | Dictionary of Welsh Biography". biography.wales. Retrieved 17 October 2019.
- Hansard 1803–2005: contributions in Parliament by James Idwal Jones