With production starting last week, Dafoe joins Ben Affleck and Henry Cavill who will reprise their title roles from this year's Batman V Superman.
Gal Gadot's Wonder Woman will also return, along with new characters Aquaman, the Flash, and Cyborg, who will be played by Jason Momoa, Ezra Miller, and Ray Fisher respectively.
Dafoe isn't the only actor making the crossover to DC.
J.K. Simmons, who played Jonah Jameson in Spider-Man, has been cast in the role of Commissioner Gordon.
