John Hadley Nicanor Hemingway was born 10 October 1923 in Toronto, Ontario, Canada to Ernest Miller Hemingway (1899-1961) and Elizabeth Hadley Richardson (1891-1979) and died 1 December 2000 New York City, New York County, New York, United States of unspecified causes. He married Byra Louise Whittlesey (1922-1988) 1949 in Paris, Île-de-France, France.
Children
| Name | Birth | Death | Joined with |
| Joan Hemingway (1950) | |||
| Margaux Louise Hemingway (1954-1996) | |||
| Mariel Hadley Hemingway (1961) | 22 November 1961 Mill Valley, Marin County, California, United States | Stephen Crisman (-) | |
Siblings
| Name | Birth | Death | Joined with |
| John Hadley Nicanor Hemingway (1923-2000) | 10 October 1923 Toronto, Ontario, Canada | 1 December 2000 New York City, New York County, New York, United States | Byra Louise Whittlesey (1922-1988) |
| Name | Birth | Death | Joined with |
| Patrick Hemingway (1928-) | |||
| Gregory Hancock Hemingway (1931-2001) | |||