John Henry O'Hara (January 31, 1905 – April 11, 1970) was one of America's most prolific writers of short stories, credited with helping to invent The New Yorker magazine short story style. He became a best-selling novelist before the age of 30 with Appointment in Samarra and BUtterfield 8. While O'Hara's legacy as a writer is debated, his champions rank him highly among the under-appreciated and unjustly neglected major American writers of the 20th century. Few college students educated after O'Hara's death in 1970 have discovered him, chiefly because he refused to allow his work to be reprinted in anthologies used to teach literature at the college level.

"O’Hara may not have been the best story writer of the twentieth century, but he is the most addictive," wrote Lorin Stein, editor-in-chief of the Paris Review, in a 2013 appreciation of O'Hara's work. Stein added, "You can binge on his collections the way some people binge on Mad Men, and for some of the same reasons. On the topics of class, sex, and alcohol—that is, the topics that mattered to him—his novels amount to a secret history of American life." His work stands out from that of his contemporary authors for its unvarnished realism.O'Hara achieved substantial commercial success in the years after World War II, when his fiction repeatedly appeared in Publishers Weekly's annual list of the top ten best-selling fiction works in the United States. These best sellers included A Rage To Live (1949), Ten North Frederick (1955), From the Terrace (1959), Ourselves to Know (1960), Sermons and Soda Water (1960) and Elizabeth Appleton (1963). Five of his works were adapted into popular films in the 1950s and 1960s.

Despite the popularity of these books, O'Hara accumulated detractors due to his outsized and easily bruised ego, alcoholic crankiness, long-held resentments and politically conservative views that were unfashionable in literary circles in the 1960s. After O'Hara's death, John Updike, a fan of O'Hara's writing, said that the prolific author "out-produced our capacity for appreciation; maybe now we can settle down and marvel at him all over again."