Duke, who will appear in the upcoming fourth season of the comedy series, will play Rita O'Reily, a career floor-greeter who is fired after heroically stopping a shoplifter.
Also set to guest star on the fourth season, which will begin this summer, are Megyn Price and Emily Rutherford. Tony Award nominee Valerie Harper (Looped) will return to "Drop Dead Diva" in the role of Judge Leslie Singer.
"Drop Dead Diva" centers on Jane (Brooke Elliott), a brilliant, plus-size attorney whose body was taken over by the spirit of Deb, "a shallow model-in-training."
Duke has been seen on Broadway in The Miracle Worker, Isle of Children and Oklahoma!. The actress re-created her performance as Helen Keller in the film version of "The Miracle Worker," earning the 1963 Academy Award for Best Supporting Actress.
For more information, visit Drop-Dead-Diva.