Jane Seymour Fonda was born on December 21, 1937 in New York City, New York, United States; the daughter of Frances Ford Brokaw (née Seymour), and Henry Fonda. She has a brother, Peter, who is also an actor, and a maternal half-sister, Frances de Villers Brokaw (aka "Pan").
In 1950, when Fonda was 12, her mother committed suicide while undergoing treatment at Craig House psychiatric hospital in Beacon, New York. Fonda's father then married socialite Susan Blanchard, just nine years his daughter's senior. Blanchard did much to provide a stable home life for them.