Sherry Mangan (full name John Joseph Sherry Mangan) was born July 27, 1904, in Lynn, Massachusetts to Irish-Catholic parents. He earned a B.A. in classical literature at Harvard University in 1925 and shortly after graduating moved to Paris. There he associated with other expatriates and was exposed to French surrealism, which influenced him both as a writer and an editor.

Mangan's first jobs in Paris were working as an editor for larus: The Celestial Visitor (1927-1928) and then for Pagany: A Native Quarterly (1930-1933). He wrote novels and short fiction (Cinderella Married, 1932; Salutation to Valediction, 1938) as well as poetry (No Apology for Poetrie and Other Poems, 1934), much of it inspired by French modernism.

He also became a fervent Marxist and Trotskyist. He was a founding member of the Socialist Workers' Party, active in organizing the French section of the International Federation of Independent Revolutionary Art, and wrote a column for the left-wing Partisan Review under the name Sean Niall.

Between 1938 and 1948 he became well-known as a journalist, frequently writing on social, cultural and political happenings in Paris. Major news magazines such as Time, Life and Fortune carried his work (his "Paris Under the Swastika," describing the occupation of the French capital, ran in the 16 September 1940 issue of Life). His short fiction and poetry appeared in a variety of periodicals including Esquire, London Mercury, Harper's, Atlantic Monthly, New Directions, and Black Mountain Review.

In the early 1940s he shifted his home base from Paris to Latin America, continuing to work as a journalist while at the same time actively supporting Trotskyist organizations such as the Fourth International. In 1953 he returned to the United States where he and his Marxist beliefs ran afoul of the House Un-American Affairs Committee. As his career and health gradually declined, he worked as a freelance editor and translator (Mozart's Idomeneo, King of Crete, 1955). He died in obscurity in 1961.