Professor Thomas is Professor of English and holder of the Emyr Humphreys Chair of Welsh Writing in English at Swansea University, having also held Visiting Professorships at the universities of Harvard and Tübingen. He is a specialist in American Poetry and the two literatures of Wales.
Since 2004 he has been Chair of the Welsh Books Council and was also Chair of its English Grants Panel (2004-2016). Previously he had spent five years as a member of the Welsh Arts Council and Chair of the Council's Literature Committee and also served for five years as Chair of the University of Wales Press. In 1996 he was elected a Fellow of the British Academy, subsequently serving a term as a member of the Academy's Council, and in 2007 was awarded an OBE for services to the two cultures of Wales.
Acting Chair of Yr Academi Gymreig (Welsh Academy of Writers) in the mid-nineties, he was elected a Fellow of the Academi in 2000, and the same year was awarded the highest honour of the National Eisteddfod of Wales. In 2009 he became a Founding Fellow of the Learned Society of Wales, and currently serves as one of the Society's Vice-Presidents. Following R. S. Thomas’s death in 2000 he was appointed literary executor of the poet’s unpublished estate and arranged the publication of the posthumous collection, Residues.
The latest of his two-dozen scholarly publications (in Welsh as well as in English) include In the Shadow of the Pulpit: Literature and Nonconformist Wales (long-listed, 2011 Welsh Book of the Year; short-listed, Roland Mathias Prize), R. S. Thomas: Serial Obsessive (short-listed, Welsh Book of the Year, 2014) and The Nations of Wales, 1890-1914 (2016).