Anna Marie "Patty" Duke (December 14, 1946 – March 29, 2016) was an American actress, appearing on stage, film, and television. Her first big break came from her Academy Award winning performance at age 16 for portraying Helen Keller in The Miracle Worker (1962); a role which she had originated on Broadway. The following year she was given her own show, The Patty Duke Show, in which she played "identical cousins" Cathy and Patty Lane. She later progressed to more mature roles such as that of Neely O'Hara in the film Valley of the Dolls (1967). Over the course of her career, she received ten Emmy Award nominations and three Emmy Awards, and two Golden Globe Awards. Duke also served as president of the Screen Actors Guild from 1985 to 1988.

Duke was diagnosed with bipolar disorder in 1982, after which she devoted much of her time to advocating for and educating the public on mental health issues.