Amy Elliot-Dunne is the main antagonist of the 2012 novel and 2014 David Fincher film Gone Girl, both written by Gillian Flynn.
She is a brilliant, calculating psychopath who contrives an elaborate plan to fake her own death and frame her husband Nick for murdering her, as punishment for Nick's infidelity.
In the film, she was portrayed by Rosamund Pike, who is also known for her roles as Miranda Frost in Die Another Day and Marla Grayson in I Care a Lot.