This was the first film to break double digits in Academy Award nominations, receiving an astonishing ten nods.
The film was shot in reverse order; Paul Muni grew his own beard for the role, and it was trimmed and darkened as he proceeded to scenes where Zola is younger. His makeup took 3-1/2 hours to apply each morning.
Considered highly contentious in France, the film wasn't granted a proper release in that country until 1952.
Studio boss Jack L. Warner, who was himself Jewish, personally ordered that the word "Jew" be removed from all dialogue in this movie about the Alfred Dreyfus Affair, apparently in order to make the drama more universal and not to offend the Nazi regime and hurt business for the film in Germany. (Source: Ben Urwand in his controversial 2013 study, "The Collaboration: Hollywood's Pact With Adolf Hitler".) However, the word does appear on screen in a single shot of Dreyfus' army file, where the audience can read: "Religion: Jew".
To research his role, Paul Muni read all of Émile Zola's works, researched the entire Alfred Dreyfus affair and experimented with different types of make-up designs with the help of leading film make-up artist, Perc Westmore.