During an interview with Howard Stern on June 19 2019, Russell Crowe mentioned that the first application of the makeup and prosthetics took 6 hours to apply. Eventually they got it down to 2 hours and 17 minutes.
Even if she'd wanted to, Gretchen Carlson could not have acted as a consultant to Naomi Watts for her portrayal of Carlson, due to a settlement agreement Gretchen signed in 2017 that prevents her from further discussing in depth what happened to her at Fox News.
In the series Russell Crowe's Roger Ailes interacts with multiple members of the Murdoch family (who own News Corp the parent company of Fox News), specifically Rupert and his son Lachlan. In 2001, Crowe purchased a $9.2 million estate in eastern Sydney, Australia from the Murdochs (in which they had previously resided in) in 2001.
Russell Crowe and Simon McBurney previously appeared in Body of Lies (2008) and Robin Hood (2010).