Ann Dowd (born January 30, 1956) is an American actress. She has played supporting roles in several films, including Green Card (1990), Lorenzo's Oil (1992), Philadelphia (1993), Garden State (2004), The Manchurian Candidate (2004), Marley & Me (2008), Side Effects (2013), St. Vincent (2014), Captain Fantastic (2016), and Hereditary (2018). Dowd appeared as Sandra in the thriller film Compliance (2012), for which she received the National Board of Review Award for Best Supporting Actress.

Dowd was a series regular on the HBO series The Leftovers (2014–2017), for which she received a Primetime Emmy Award nomination for Outstanding Guest Actress in a Drama Series. In 2017, she began playing Aunt Lydia on the Hulu series The Handmaid's Tale, for which she won the Primetime Emmy Award for Outstanding Supporting Actress in a Drama Series.