Appeared in films first in 1925.
Her name was choosen by a competition
Parents were divorced before or shortly after her birth.
Mother remarried and Joan worked in family vaudeville theatre under the name of Billie Cassin.
Aged 6 she spent a year in bed because of a foot injury.
Couldn't sing (see Hollywood Revue of 1929) but she could dance, useful in the 20's.
Her failed marraiges included, Fairbanks Jr, Franchot Tone, Philip Terry.
Also married Alfred Steele, Pepsi-Cola chairman and when he died in 1959 became the first female director of the company.
Was the subject of her daughters unpleasant book, 'Mommie Dearest.'