Evans was born on 23 September 1930 in Llanfynydd, Carmarthenshire, Wales.
[3] Evans lectured at the University of Wales, Swansea from 1957 to 1978, rising to become a professor.
He was appointed as a Fellow of the British Academy in 1983, having delivered the Academy's Sir John Rhys Memorial Lecture in 1977, named in honour of the first Oxford Celtic Professor.
His particular research interest was early Celtic culture throughout Europe, dealing with its relationship with that of the classical world, and in the history of the Insular Celtic languages, including the early literatures of Wales and Ireland.
[1] A volume of essays on these topics by fellow Celticists was published in 1995 in honour of his 65th birthday; Essays in honour of Professor D. Ellis Evans on the occasion of his sixty-fifth birthday.