Amanda Peet grew up in New York with her older sister and their parents, Charles, a lawyer, and Penny, a social worker. She made an unconventional stage debut at the age of three when she jumped onto the stage during a play; yet, despite this early start, she later studied acting more as a hobby than anything else. She studied history at Columbia University where a drama professor convinced her to audition for acting teacher Uta Hagen, with whom she later went on to study for a four-year period; during which time, she participated in the off-Broadway revival of Clifford Odets' "Awake and Sing." She supported herself during the audition phase of her career by waitressing and with the residual checks she received from a Skittles candy commercial. Perseverance and hard work paid off, and in 1995, she was cast in a guest-starring role on the hit series Law & Order.

Her feature film debut came in 1995 in the movie Animal Room. For a while after, Amanda continued to find steady work, but also found herself appearing in a depressingly large number of indie films that were never picked up. She did however, meet her boyfriend Brian Van Holt on the set of indie movie Whipped. Her turn as the ditzy hit-woman with the heart of gold in the hit comedy The Whole Nine Yards opposite Bruce Willis, that took her from supporting role status to leading lady. That same year she was voted one of the 50 Most Beautiful People In The World By People Magazine.
Graduated from Columbia University in 1994. Voted one of the 50 most beautiful people in the World 2000 by People Magazine. Was maid of honor at actress Lauren Holly's wedding to Francis Greco. [10 March 2001] Worked at "City Crab" in New York before hitting it big. (Source: Interview, Larry King Live, 10 February 2000). Replaced Amelia Heinle (the original Jack) in the Jack & Jill pilot episode. Attended Friends Seminary (k-12) with actor Liev Schreiber: when he was a senior she was in the 7th grade. Educated at an all-girls' prep school in London. Her father, Charles, has been a prominent corporate attorney in New York City for decades. Ranked #44 in Stuff magazine's "102 Sexiest Women in the World" (2002). Engaged to David Benioff [July 22, 2005]. Has one older sister. Named #87 in FHM magazine's "100 Sexiest Women in the World 2006" supplement. (2006). Did not learn to drive until she moved to L.A. in 2000. Her character, "Jordan McDeere" on Studio 60 on the Sunset Strip, is based on former NBC president Jamie Tarses. Mother: the former Larry (sic) Levy, who was born in England. At age 35, she gave birth to her first child. Daughter, Frances Pen was born on February 20, 2007 weighing 6 lbs, 10 oz. The baby's middle name is in honor of Amanda's mom, Penny. Amanda and David were married at her alma mater, Friends Seminary high school, in New York City.