Elizabeth Greer Feldstein (born June 24, 1993) is an American actress. She first gained recognition for starring roles in the comedy film Neighbors 2: Sorority Rising (2016), the comedy-drama Lady Bird (2017), and the coming-of-age comedy Booksmart (2019), the latter of which earned her a Golden Globe nomination for Best Actress in a Comedy or Musical.

Feldstein has performed on the Broadway stage, debuting as Minnie Fay in Hello, Dolly! (2017–18) and playing the lead role of Fanny Brice in the first revival of Funny Girl (2022), for which she was nominated for the Drama League Award for Outstanding Performance. In 2021, she played Monica Lewinsky in the third season of the FX anthology American Crime Story: Impeachment.