Williams was orphaned as a young boy and raised by an aunt. He was a gardener, then worked for a wholesaler and then began to preach in 1878.
He wrote poetry and rose to become Archdruid of Wales (the highest honor in Welsh poetry; Pedrog is his bardic name) from 1928 to 1932, head of the Welsh Independent [Congregationalist] Church in 1927 and editor of Y Dysgedydd from 1922 to 1928. He won more bardic competitions than any other poet in the history of Welsh literature.