"Her transformations are now legendary, her performances are so bold and daring. She doesn’t shy away from hard subjects. She dives in, with intensity, humanity, depth and vulnerability. She gives so much heart to even her toughest characters," she continued.
Kidman also noted that Theron had to "overcome so many obstacles" to make sure Bombshell was produced and that she had portrayed journalist Megyn Kelly "with absolute commitment and precision."
The Big Little Lies star claimed Theron had pulled off a "high wire act" in "having the courage to embody a disturbing inner conflict, and tell the messy, controversial back story, without which we might never have had the #metoo movement."
Instyle reported that Theron was visibly emotional at Kidman's gushing words, particularly during the moment when she referred to her as her "hero."
"It was an absolute joy to be able to give this to you tonight @CharlizeAfrica. You’re the real deal!" Kidman wrote on Instagram afterwards.
The actresses also worked with Margot Robbie on the highly-anticipated film.
Directed by Jay Roach, Bombshell will delve into the sexual harassment allegations made against the late Fox News founder, Roger Ailes.
Bombshell will premiere on December 20, 2019.