A twentieth-century, American-born fiction writer, he is best known for works such as The Grandmothers (1927) and The Pilgrim Hawk: A Love Story (1940). He was a prominent figure in the American expatriate community in Europe.
He studied at the University of Chicago. He began his literary career as a poet, but quickly turned to writing novels and short stories.
He was the model for the character of Robert Prentiss in Ernest Hemingway's classic novel, The Sun Also Rises.
Wescott's relationship with partner Monroe Wheeler began in 1919 and ended only with Wescott's death in 1987.
He lived in France, where he was an acquaintance of fellow expatriate author Gertrude Stein.