Catherine Ann Keener (born March 26, 1959) is an American actress. She is considered one of the most reliable performers in independent cinema; she is known for her roles as dissatisfied and melancholic but sympathetic women in independent films, as well as supporting roles in studio pictures. She was nominated twice for the Academy Award for Best Supporting Actress — for the film Being John Malkovich (1999) and for her portrayal of writer Harper Lee in the film Capote (2005).

Keener also appeared in the films The 40-Year-Old Virgin (2005), Into the Wild (2007), Synecdoche, New York (2008), and Get Out (2017), which received critical acclaim. Keener is the muse of director Nicole Holofcener, and she has appeared in each of her first five films. She also appeared in each of the first four films by director Tom DiCillo and in three films by director Spike Jonze. From 2018 to 2020, she starred in the Showtime tragicomedy series Growing Up.