Sydney Bernice Sweeney (born September 12, 1997) is an American actress. She first gained attention for appearing in the television series Everything Sucks! (2018), The Handmaid's Tale (2018), and Sharp Objects (2018). In 2019, she was featured in Quentin Tarantino's film Once Upon a Time in Hollywood.

For her roles as troubled teenagers in the HBO series Euphoria (2019–present) and The White Lotus (2021), she received nominations for two Primetime Emmy Awards in 2022. In 2023, Sweeney gained praise for portraying Reality Winner in the film Reality.

Early life
Sydney Bernice Sweeney was born on September 12, 1997, in Spokane, Washington, to Lisa (née Mudd) and Steven Sweeney. Her mother is a lawyer and her father works in the medical field. She has a brother, Trent. Sweeney was raised in northwestern Idaho in the state's Panhandle region along the Washington border, at a rural lakeside home that her family has inhabited for five generations. Sweeney has said she has a "religious family".

Sweeney attended Saint George's School in Spokane. She was active in numerous athletics: "I was in every single sport possible", she said. "I was on the soccer team, the baseball team, the snow slalom ski team, I was wakeboarding." Sweeney also studied multiple languages and graduated with top grades. She became interested in acting after auditioning to be an extra in an independent film that was shooting in the Spokane area. To convince her parents to allow her to pursue acting, she presented them with a five-year business plan. Sweeney began to audition and book commercial acting jobs in Seattle and Portland, Oregon, where the family temporarily resided, until choosing to relocate to Los Angeles, California, when she was 14 years old.