Amanda Peet (born January 11, 1972) is an American actress. She began her career with small parts on television before making her feature film debut in Animal Room (1995). Her portrayal of Jill St. Claire in The Whole Nine Yards (2000) brought her wider recognition, and she has since appeared in a variety of films, such as Saving Silverman (2001), High Crimes, Changing Lanes, Igby Goes Down (all 2002), Something's Gotta Give, Identity (both 2003), Melinda and Melinda (2004), A Lot Like Love, Syriana (both 2005), The X-Files: I Want to Believe (2008), 2012 (2009), Gulliver's Travels (2010), Identity Thief, and The Way, Way Back (both 2013).

Outside of film, Peet played Jacqueline Barrett on The WB's Jack & Jill (1999–2001), Jordan McDeere on NBC's short-lived Aaron Sorkin series Studio 60 on the Sunset Strip (2006-2007), Tina Morris on HBO's Togetherness (2015–2016), Jules on IFC's Brockmire (2016–2020), Betty Broderick on the second season of Bravo's Dirty John (2020), and Beth Gallagher in the Paramount+ adaptation of Fatal Attraction (2023). In 2021, she wrote and co-executive produced The Chair for Netflix. Peet is married to American screenwriter David Benioff, with whom she has three children.