Anna Marie "Patty" Duke (born December 14, 1946) is an American actress of stage, film, and television. She was able to make the rare successful transition from child star (winning an Academy Award for Best Supporting Actress at age 16) to award-winning adult actress. She was elected president of the Screen Actors Guild (1985 to 1988).

Duke was diagnosed with bipolar disorder or manic depression in 1982, and since then has devoted most of her time to advocating and educating the public on mental health issues.

Duke was born Anna Marie Duke in Elmhurst, Queens, New York, the daughter of Frances (née McMahon), a cashier, and John Patrick Duke, a handyman and cab driver. Her father was Irish American and her maternal grandmother was German.