| Year | Book | Prose | Publisher | Notes |
| 1963 | The Penguin Book of Religious Verse | Introduction | Penguin | Included in Selected Prose. |
| 1964 | Selected Poems of Edward Thomas | Introduction | Faber & Faber | - |
| 1967 | Selected Poems of George Herbert's Verse | Introduction | Faber & Faber | - |
| 1968 | The Mountains | The Mountain | Chilmark Press | Included in Selected Prose. |
| 1971 | A Choice of Wordsworth's Verse | Introduction | Faber & Faber | Included in Selected Prose. |
| 1983 | Selected Prose | The Depopulation of the Welsh Hill Country(1945), Some Contemporary Scottish Writting(1946), Two Chapels(1948), Anglo-Welsh Literature(1952), The Qualities of Christmas(1959), Introduction to The Penguin Book of Religious Verse(1963), Words and Poet(1964), A Frame for Poetry(1966), The Mountains(1968), The Making of a Poem(1969), Introduction to A Choice of Wordsworth's Verse(1971), The Paths Gone By(1972), [Review of ] Buy My Heart at Wounded Knee(1974), Where Do We Go From Here?(1974), Abercuawg(1976), The Creative Writer's Suicide(1978), If I had the Language...(1980), Unity(1988) | Poetry Wales Press | Edited by Sandra Anstey. |
| 1985 | Neb | - | Caernafon: Gwasg Gwynedd | His first autobiography written in Welsh covers from his birth to his retirement from the Church in Wales. The English translation of this is published in Autobiographies. |
| 1992 | Cymru or Wales? | - | Gomer | One of series of personal essays on aspects of life in contemporary Wales. Series Editor: Meic Stephens. |
| 1993 | Miraculous Simplicity -Essays on R.S.Thomas | Autobiographical Essay(1986) | The University of Arkansas Press | This essay was reprinted from Comtemporary Authors: Autobiographical Series Volume 4 (Detroit: Gale, 1986). The book also contains "Probings: An Interview with R.S.Thomas" (1990) by Ned Thomas and John Barnie. |
| 1997 | Autobiographies | *Former Paths [The Paths Gone By](1972), *The Creative Writer's Suicide(1977), Neb[No one](1985), A Year In Llyn(1990) | Orion/Phoenix | Translated from Welsh by Jason Walford Davis. *indicates an essay included in Selected Prose. |
| 2009 | R.S. Thomas: Letters to Raymond Garlick 1951-1999 | - | Gomer | Edited, with an Introduction and Notes, by Jason Walford Davies |
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