The "Argo" star will play the sadistic comic book serial killer in the film, about a group of female anti-heroes.
According to Deadline, the character was first introduced in "Batman: Shadow of the Bat" in 1992.
The DC Comics film, in which Margot Robbie will reprise her "Suicide Squad" role as Harley Quinn, is to be directed by Cathy Yan.
Mary Elizabeth Winstead will also star as Huntress, alongside Jurnee Smollett as Black Canary, and Rosie Perez, who has been cast as Renee Montoya/The Question, while Ewan McGregor has been tapped as Zsasz's criminal mastermind boss Black Mask, aka Roman Sionis.
"Birds of Prey" is set to be released in February, 2020.