Cynan was born in Pwllheli, the son of Richard Albert Jones and Hannah Jane (née Evans) his father was the proprietor of the Central Restaurant in Penlan Street, Pwllheli. He was educated at Pwllheli Grammar School and the University College of North Wales where he graduated in 1916.
On graduation Cynan joined the Welsh Student Company of the RAMC, serving in Salonika and France serving initially as an ambulance man and then as the company's pastor. His wartime experience had a profound effect on his poetic works, to such an extent that Alan Llwyd claims that Cynan, not Hedd Wyn, is the premier Welsh war poet of the First World War. Hedd Wyn's poems relating to the war were written before he had enlisted and he was killed before he could recount his experience of the war in his muse. Cynan, however, gives the best descriptions of the gritty atrocities of war, and the impact of war on a man's body as well as his spirit.
After the war, Cynan entered Coleg ym Pwllheli to train for the ministry of The Presbyterian Church of Wales. He was ordained at Penmaenmawr Caernarfonshire in 1920 where he served as minister until 1931 when he relinquished his calling having been appointed a tutor in the Extramural Department of the University College of North Wales specialising in Drama and Welsh Literature. Despite having given up his ministry Cynan continued to accept regular preaching engagements, and was one of the most popular preachers of his day on the nonconformist preaching circuit in Wales.
Whilst working in the University, Cynan lived in Menai Bridge Anglesey, but in his best known poem he expressed a wish to retire to Aberdaron Caernarfonshire,
Apart from being an important figure in Welsh poetic circles Cynan was also influential in the field of Welsh drama. He wrote two full-length plays: Hywel Harris won the premier Eisteddfod prize for drama in 1931. He was commissioned to write an exemplary play for the National Eisteddfod in 1957 – his offering Absolom Fy Mab was accepted to great critical acclaim in Welsh dramatic circles as were his translations of English Language plays John Masefield's Good Friday and Norman Nicholson's The Old Man of the Mountain.
In 1931 he was appointed reader of Welsh plays on behalf of the Lord Chamberlain, a post which he held till the abolition of censorship in 1968. He was seen as a liberal censor, having allowed James Kitchener Davies' drama Cwm Glo, a play full of "filth and depravation" to be performed after it won the drama prize in the 1934 Eisteddfod.
Cynan made regular appearances on Welsh language radio and TV programmes, and he was the subject of the first Colour TV programme broadcast in the Welsh Language Llanc o Lŷn.
Cynan is best known for his huge influence in the modernisation of the National Eisteddfod. He was Archdruid twice, the only person to have been elected to the position for a second term. His two terms were from 1950 till 1954 and from 1963 till 1966. He was the Recorder of the Gorsedd of Bards in 1935, and joint-secretary of the National Eisteddfod Council in 1937. He was the First Archdruid to accept that the Gorsedd was the invention of Iolo Morganwg and that it had no links to antiquity or with the ancient Druids, thus healing rifts between the academic and ecclesiastical establishments and the Eisteddfod movement.
Cynan is also responsible for designing the modern ceremonies of the Crowning and the Chairing of the Bard in the Eisteddfod as they are now performed, by creating ceremonies which, he thought, reflected the spirit of the Welsh Nation.
Cynan was also prominent as a National Eisteddfod competitor. He won the crown in 1921 at the Caernarfon National Eisteddfod for his poem Mab y Bwthyn (A cottage son), which recounted the experience of a Welshman in the Great War. He won the Crown for his poem Yr Ynys Unig (The Lonely Isle) in the Mold Eisteddfod of 1923; his third crowned poem, Y Dyrfa / The Crowd ( Bangor 1931 ), described a rugby match - the first time such a topic was attempted in Welsh poetry. To add to his three crowns Cynan was also awarded the chair in 1924 for a poem I'r Duw nid adwaenir (To the unknown God), which is a unique achievement in that it is the only time that the chair has been awarded to a winning poem that was not written within the strict rules of Cynghanedd.
Cynan also adjudicated many times at the National Eisteddfod.
Cynan was awarded the honorary degree of D.Litt. by the University of Wales in 1961.
He was awarded the freedom of the borough of Pwllheli in 1963.
He was appointed C.B.E. in 1949, and knighted in 1969.
Cynan was married twice: first, in 1921, to Ellen J. Jones of Pwllheli; they had one son and one daughter. Ellen died in 1962. In 1963 he married Menna Meirion Jones of Valley, Anglesey.
Cynan died on 26 January 1970 and was buried in the yard of Ynys Tysilio Church, Church Island, Menai Strait, Anglesey.Telyn y Nos (1921)
Hywel Harris (1932)
Absalom Fy Mab (1957)
Ffarwel Weledig (1946)