Jane Fonda was born in New York City, to actor Henry Fonda and socialite Frances Brokaw (née Seymour). She was named after Lady Jane Seymour, the third wife of King Henry VIII.

Jane's mother, Frances, was the second of Henry Fonda's five wives, and was formerly married to millionaire George Brokaw, the onetime husband of writer Clare Boothe Luce. After voluntarily seeking help at an asylum, Frances Fonda committed suicide in October 1950, when Jane was 12 years old. In Fonda's 2005 memoir, the actress wrote that while researching the book, she was granted access to her mother's psychiatric records and discovered that her mother had been sexually molested as a child, a trauma that doubtless contributed to her later emotional and mental instabilty.