Walter will play Barbara Latham, a wealthy university donor who may put the moves on Leonard (Johnny Galecki). The episode will also feature Josh Malina ("The West Wing") as a university president.
Walter, known for her work on the Fox series "Arrested Development," appeared on Broadway in Rumors, A Severed Head, Photo Finish, Night Life and Advise and Consent.
"The Big Bang Theory" airs Thursdays at 8 PM ET on CBS.