Early on, director Fred Zinnemann actually considered casting Meryl Streep in the title role. However, as Streep was almost totally unknown as an actress - she had only one play to her credit, and never appeared in a film - Zinnemann decided to cast Dame Vanessa Redgrave instead.
Jane Fonda was originally cast as Julia. However, when the producers had trouble casting the role of Lillian Hellman, they decided to recast Fonda in the lead.
During the casting process, both Jane Fonda and Dame Vanessa Redgrave's names were mentioned as possible stars for the film. The producers initially vetoed both actresses on the advice of the publicity department, fearing that the absolute worst option would be to cast Fonda and Redgrave, both of whom were known for their outspoken political beliefs, in a film together. In the end, of course, both actresses were cast and the film went on to great critical and box office success.
When Jason Robards failed to appear at the 1978 Academy Awards, host Bob Hope quipped that "He must be off playing bridge with George C. Scott and Marlon Brando", who both famously had rejected their Oscars in the early 1970s.
Lillian Hellman: the source story author and the film's primary subject as the shadowy person sitting in the fishing boat at the beginning and end of the film. Jane Fonda did the voice-over. This appearance is Hellman's only film.