John James Williams (8 October 1869 – 6 May 1954), commonly known by his bardic name of "J.J.", was a Welsh poet and served as Archdruid of the National Eisteddfod of Wales from 1936 to 1939.
Williams was born in Taigwynion, near Tal-y-bont, Cardiganshire. He was the eldest of twelve children born to William and Elizabeth Williams. As was fairly usual in that era the parents attended different nonconformist chapels. His mother was a member at Pen-y-Garn, the Calvinistic Methodist church at Rhydypennau while his father attended Bethel Independent church at Tal-y-bont. William Williams was a lead miner and due to lack of work in the local industry he went to work for some time in 1879-80 at the collieries in Mountain Ash. In 1882 the whole family settled in Penrhiwceibr in the Aberdare valley where they became members at Carmel chapel. Shortly afterwards they moved to Ynysybwl and joined Tabernacle, where the young Williams began preaching while working as a miner.
Williams had received his elementary education at Pwllglas Sunday School and at Rhydypennau School in his native Cardiganshire, but left at an early age. While working underground he was accepted as a student to prepare for the nonconformist ministry, and attended Pontypridd Academy which was run by E. Dunmore Edwards. In 1891, he was accepted as a student at the Memorial College, Brecon and spent the first years of study at University College, Cardiff, where he excelled in his studies of Welsh language and literature.
Williams was ordained at Bethania, Abercynon, on 22 July 1895. In 1897, he moved to Moriah, Rhymney. After six years in Rhymney he moved to Seilo, Pentre, Rhondda, where he succeeded Lewis Probert.