According to an in-depth article on Joan by Rod Labbe in "Classic Images" magazine, Joan was offered the role of Karen Holmes, the Army wife and adulteress, in James Jones' From Here to Eternity (1953) by Columbia after it had purchased the film rights. Joan was subsequently forced to decline the role because, at the time, she was embroiled in a particularly ugly custody battle over daughter Deborah from William Dozier. Leaving California to film extensively in Hawaii would have jeopardized Joan's case. The part went to second choice Deborah Kerr, who earned an Oscar nomination. Joan later replaced Ms. Kerr on Broadway in the original production of "Tea and Sympathy".
Allegedly was treated horribly by Laurence Olivier during their time together on the set of Rebecca (1940) as he had campaigned for his then-girlfriend Vivien Leigh to be given the part of Mrs. De Winter.
As of 2011 she is the last surviving cast member of George Cukor's "The Women" (1939).
At the age of three she scored 160 on an infant IQ test.
Attended Oak Street School in Saratoga, California.
Became pregnant twice in 1964, at the age of 46, but miscarried both times.
Daughter of film and stage actress Lillian Fontaine
Daughter, Martita, born 3 November 1946, adopted 1952. Ran away in 1963. When Joan found her she was refused contact with the child on the premise that her Peruvian adoption was not valid in the United States. Martita maintained a relationship with her sister Debbie, but never spoke to or saw Joan again.
First husband Brian Aherne had a friend call her the night before their wedding to tell her he had cold feet and couldn't marry her. Joan told the friend to tell him it was too late to call it off, that he had better be at the altar the next morning to marry her, and he could divorce her afterwards if he wanted. He was there at the altar and they remained married six years, never mentioning this incident to each other.
Fontaine is the younger sister of actress Olivia de Havilland.
Fontaine's mother, Lilian Augusta Ruse (1886–1975), was an actress known professionally as Lillian Fontaine.
Head of jury at the Berlin International Film Festival in 1982
Her autobiography No Bed of Roses was published in 1979. Ex-husband William Dozier thought a more appropriate title should have been No Shred of Truth.
Her personal favourite film of hers is The Constant Nymph (1943).
In a rare act of reconciliation, Joan and her sister Olivia de Havilland celebrated Christmas 1962 together with their then-husbands and children.
In Italy, almost all of her films were dubbed by Lidia Simoneschi. She was occasionally dubbed by Rosetta Calavetta and Renata Marini. She was dubbed once by Micaela Giustiniani in The Women (1939), once by Dina Perbellini and once by Paola Barbara in Suspicion (1941).
Is one of three Japan-born actresses to have won an Academy Award. The others are her sister Olivia de Havilland and Miyoshi Umeki.