Gary Oldman wanted to wear elaborate prosthetic makeup to closely resemble the historical Herman J. Mankiewicz but was persuaded otherwise by David Fincher, who wanted minimal makeup for capturing a more intimate performance.
Shot on RED's Helium Monochrome 8K cameras, no color version of this film exists.
The broadcaster announcing the person accepting the Academy Award for best original screenplay on behalf of Mankiewicz and Welles at the end of the movie is Ben Mankiewicz, a grandson of Herman J. Mankiewicz. Ben Mankiewicz is a presenter for Turner Classic Movies, which frequently airs films by Herman Mankiewicz and his brother Joseph. Ben's father, Frank, is portrayed briefly in Mank by the uncredited child actor Matteo Menzies; Frank Mankiewicz was Senator Robert F. Kennedy's press secretary, campaign director for the Democratic presidential nominee George McGovern, and the first president of National Public Radio.
For most of December 2019, the film was shot at the Kemper Campbell Ranch in Victorville, California, where Herman J. Mankiewicz wrote Citizen Kane (1941). Considering the ranch changed very little over the years, the location helped reflect the time period of the late 1930s.