Seán O'Faoláin was born John Francis Whelan on February 22, 1900, in Cork. He attended the Presentation Brothers secondary school and later University College, Cork, where he received his B.A. in modern literature.

In 1917, after a visit to the Gaeltacht region, O'Faoláin Gaelicized his name and joined the Irish Republican Army (IRA). In the early 1920s he served as an "irregular", worked in a bomb shop, and was appointed director of publicity for the Dublin division. Disaffection with the republican cause ultimately resulted in his resignation from the IRA and his return to Cork.

He received an M.A. in English at the National University of Ireland, taught at a Christian Brothers school in Ennis for a year, obtained a second M.A. in Irish, and published his first short story, "Lilliput," in The Irish Statesman, which won him the Harkness Commonwealth Fellowship to study in the United States. From 1926-1929 he studied philology at Harvard University under George Lyman Kitteredge. He married Eileen Gould in 1927, and after Harvard they lived in London, where O'Faoláin taught at St. Mary's College while completing his first collection of stories, Midsummer Night Madness.

In 1933, O'Faoláin returned to Wicklow, Ireland with his family. He freelanced for The Spectator, The New Statesman, and wrote his first novel, A Nest of Simple Folk. He later established the literary magazine, The Bell, and he served as its editor and manager for six years. In retirement, O'Faoláin lived with Eileen in Dun Laoghaire. In 1989, he entered Alcare House, a nursing home in Dublin, where he died after a brief illness in 1991.

Source:

Lynch, M. Kelly. "Sean O'Faoláin." Dictionary of Irish Literature Revised and Expanded Edition M-Z. Ed. Robert Hogan. Westport, CT: Greenwood Press, 1996. 957-962.