The production will open April 3, 2005, after previews from March 8. The Belasco is the theatre.
The 54-year-old Sadler has played supporting roles in such high-profile films as "The Green Mile," "The Shawshank Redemption," "Die Hard II" and the current "Kinsey." He had also had roles in the television series "Roswell," "Roseanne" and " Star Trek: Deep Space Nine." He began his career in the New York theatre and plays Sgt. Toomey in the Broadway premiere of Neil Simon's Biloxi Blues. He won a 1981 Obie Award for his work in Len Jenkins' Limbo Tales. Other Off-Broadway credits include Cloud Nine and Lennon.
Sadler's involvement has not been officially announced.
As previously reported, Washington is set to star as one of the most noted of political and personal betrayers, Brutus. Daniel Sullivan (Proof), a director not typically associated with the Bard, will stage the political tragedy.
The production will be produced by Carole Shorenstein Hays and Freddy DeMann. The Belasco's current resident, Dracula the Musical, will shutter on Jan. 2, it was announced Dec. 7.
Washington, 49, earned Oscars for his turns in the films "Training Day" and "Glory." The actor is also known for his work in "Philadelphia," "Malcolm X," "The Hurricane," "The Manchurian Candidate" and his recent directorial debut, "Antwone Fisher." Washington last appeared on Broadway in 1988's Checkmates.
Director Sullivan staged this season's Sight Unseen and is currently slated to helm two other upcoming Manhattan Theatre Club productions: Brooklyn Boy and After the Night and the Music.
Julius Caesar hasn't been seen on Broadway since 1950. It was recently produced in Central Park by the Public Theater, with a cast including Jeffrey Wright.