Most of John Wilson Foster's books have been on his native Ireland's literature and culture, on which he is regarded as an expert of international standing.
The Achievement of Seamus Heaney (Lilliput, 1995) was written to celebrate the poetry of the Irish Nobel laureate whom Foster has known and on whom he had written as early as 1974.
Other books on Irish literature include Fictions of the Irish Literary Revival: A Changeling Art (Syracuse University Press, 1987), The Cambridge Companion to the Irish Novel (ed. 2006) and Irish Novels 1890-1940 (Oxford UP, 2008).
Influential explorations of twentieth-century and twenty-first century Irish culture include Colonial Consequences (Lilliput, 1991) and Between Shadows (Irish Academic Press, 2009).