Dianne Evelyn Wiest (; born March 28, 1946) is an American actress.

Wiest has won the Academy Award for Best Supporting Actress twice, for Hannah and Her Sisters (1986) and Bullets over Broadway (1994), both directed by Woody Allen. She appeared in three other of Allen's films: The Purple Rose of Cairo (1985), Radio Days (1987) and September (1987). She also starred in Ron Howard's comedy-drama film Parenthood (1989), for which she received her second Academy Award nomination. Wiest has received a Golden Globe Award and two Screen Actors Guild Awards, as well as a BAFTA Award nomination.

Her other films include Footloose (1984), The Lost Boys (1987), Bright Lights, Big City (1988), Edward Scissorhands (1990), Little Man Tate (1991), The Birdcage (1996), Practical Magic (1998), Dan in Real Life (2007), Synecdoche, New York (2008), Rabbit Hole (2010), and Sisters (2015).

Wiest also starred in the HBO drama series In Treatment (2008–2009) and currently stars in the CBS comedy series Life in Pieces (2015–present). For her work on television, she has received two Primetime Emmy Awards.