Born in Lasynys Fawr (grid reference SH596327) near Harlech, Gwynedd, Wynne excelled at school and entered Jesus College, Oxford on 1 March 1692. There is historical debate as to whether or not he graduated, and little evidence to support either claim, but local tradition suggests that he was studying law before he was convinced to take Holy Orders by his friend Humphrey Humphreys, Bishop of Bangor and, afterwards, of Hereford. He was ordained a priest in December 1704. During his life, he was priest of the parishes of Llandanwg, Llanbedr and Llanfair.
Although a respected priest, Welsh translator and hymn writer, Wynne is remembered today largely because of his literary output. His Gweledigaetheu y Bardd Cwsc ('Visions of the Sleeping Bard'), first published in London in 1703, is regarded as a Welsh language classic. It is generally said that no better model exists of such 'pure' idiomatic Welsh, before writers had become influenced by English style and method. On the title page of the book, the words Y Rhann Gyntaf ('The First Part') appear; it has been suggested that Wynne had indeed written a second part - a 'Vision of heaven' - but on hearing that he had been charged with plagiarism of the first part, destroyed the manuscript. The charges of plagiarism were never substantiated and are, today, regarded as false.
Wynne's later life is as obscure as the early part of his life, and we know little of what became of him after the publication of the Gweledigaethau. He was buried under the altar at Llanfair (near Harlech).