Dianne Wiest (born 28 March 1948) is an American actress. She has had a successful career on stage, television, and film, and has won two Academy Awards, two Emmy Awards and a Golden Globe Award. Wiest has also been nominated for a BAFTA Award.

Wiest was born in Kansas City, Missouri. Her father was a college dean and former psychiatric social worker for the U.S. Army, and her Scottish-born mother, Anne, worked as a nurse; her parents met in Algiers. She has two brothers: Greg and Don Wiest. Wiest's original ambition was to be a ballerina, but in late high school she switched her goal to theatre. She made her film debut in It's My Turn (1980), but did not establish herself as a film actress until her work for Woody Allen in the 1980s.

Wiest studied theatre at the University of Maryland, leaving after her third term in order to tour with a Shakespearean troupe, eventually appearing in a supporting role in the New York Shakespeare Festival production Ashes. She appeared at the Long Wharf Theatre in New Haven, CT, playing the title role in Ibsen's Hedda Gabler and understudied off-Broadway in Kurt Vonnegut's Happy Birthday, Wanda June at the Lucille Lortel Theatre. She made her Broadway debut in Robert Anderson's Solitaire/Double Solitaire, taking over in the role of the daughter in 1971. She landed a four-year job as a member of the Arena Stage in Washington, D.C., appearing in many plays including a memorable Emily in Our Town, Honey in Who's Afraid of Virginia Woolf?, and leading roles in S. Ansky's The Dybbuk, Maxim Gorky's The Lower Depths and Shaw's "Heartbreak House." She also toured the USSR with the Arena Stage Company.