O'Connor is primarily known for her short stories. She published two books of short stories: A Good Man Is Hard to Find (1955) and Everything That Rises Must Converge (published posthumously in 1965). Many of O'Connor's short stories have been re-published in major anthologies, including The Best American Short Stories and Prize Stories.
O'Connor's two novels are Wise Blood (1952) (made into a film by John Huston) and The Violent Bear It Away (1960). She also has had several books of her other writings published, and her enduring influence is attested by a growing body of scholarly studies of her work.
Fragments exist of an unfinished novel tentatively titled Why Do the Heathen Rage? that draws from several of her short stories, including "Why Do the Heathen Rage?," "The Enduring Chill," and "The Partridge Festival."
Her writing career can be divided into four five-year periods of increasing skill and ambition, 1945 to 1964:
- Postgrad Student: Iowa Writers' Workshop, first published stories, drafts of Wise Blood. Literary influences include Nathaniel Hawthorne, Edgar Allan Poe, Henry James
- Early: Wise Blood completed and published. In this period, satirical elements dominate. Influences include Jacques Maritain
- Mid: A Good Man Is Hard to Find published, The Violent Bear It Away written and published. Influences include Friedrich von Hügel. In this period, the mystical undercurrents begin to have primacy.
- Mature: Everything That Rises Must Converge written. Influences include Pierre Teilhard de Chardin and Mary Anne Long. In this period, the notion of grotesque is expanded to include the good as grotesque, and the grotesque as good.