Amy Beth Dziewiontkowski (born May 3, 1968), known professionally as Amy Ryan, is an American actress of stage and screen. A graduate of New York's High School of Performing Arts, she is an Academy Award nominee and two-time Tony Award nominee.

Ryan began her professional stage career in 1987 and made her Broadway debut in 1993 as a replacement in the original production of The Sisters Rosensweig. She went on to receive Tony Award nominations for Best Featured Actress in a Play for the 2000 revival of Uncle Vanya and the 2005 revival of A Streetcar Named Desire. She was nominated for an Academy Award for Best Supporting Actress for her performance as Helene McCready in the 2007 film Gone Baby Gone. The role also earned her a Golden Globe nomination and won her a Critics' Choice Award. Her other films include Changeling (2008), Win Win (2011) and Birdman or (The Unexpected Virtue of Ignorance) (2014). On television, she played Beadie Russell in HBO's The Wire (2002–2008), Holly Flax in NBC's The Office (2008–2011) and Adele Brousse in HBO's In Treatment (2010). In 2021, she had a main role in the Hulu comedy series Only Murders in the Building.