Fox was born in Wheeling, West Virginia to Marie (née Oglseby) and Frederick Fox. She was married to Darryl F. Zanuck from 1924 until they separated in 1956. They had three children, one of them was movie producer Richard D. Zanuck. Fox died on October 14, 1982 in Palm Springs, California from emphysema and from cerebral thrombosis, she was 80 years old.