Eileen is a 2015 novel by Ottessa Moshfegh, published by Penguin Press. It is Moshfegh's first novel. It won the Hemingway Foundation/PEN Award for debut fiction and was shortlisted for the 2016 Man Booker Prize and the 2015 National Book Critics Circle Award. The novel was adapted into a 2023 film.

Ottessa Charlotte Moshfegh is an American author and novelist. Her debut novel, Eileen (2015), won the Hemingway Foundation/PEN Award, was shortlisted for the Booker Prize, and was a fiction finalist for the National Book Critics Circle Award. Moshfegh's subsequent novels include My Year of Rest and Relaxation, Death in Her Hands, and Lapvona.