What was the name of Hemingway's third son?

Ernest Hemingway’s third son was Gregory Hemingway. Born on November 12, 1931, in Kansas City, Missouri, Gregory was the youngest child of Ernest Hemingway and his second wife, Pauline Pfeiffer.

Gregory followed a different professional path from his famous father. He studied medicine at the University of Miami and became a physician, while also writing a memoir, Papa: A Personal Memoir, published in 1976. He spent parts of his life in New York, Montana, and other places shaped by the Hemingway family’s frequent travel.

Historical sources commonly identify him as Gregory Hemingway, but later accounts also refer to Gregory as Gloria Hemingway. That later name reflects her gender transition and is important context when reading modern biographies. The other two Hemingway sons were John Hadley Nicanor, known as Jack, and Patrick; Gregory was the youngest of the three.