Pretty Little Liars is an American slasher teen drama mystery television series created by Roberto Aguirre-Sacasa and Lindsay Calhoon Bring for Max. It is the fourth television series in the Pretty Little Liars franchise, which is based on the novel series written by Sara Shepard, and set within the same continuity as the previous series. The series features an ensemble cast, headed by Bailee Madison, Chandler Kinney, Zaria, Malia Pyles, and Maia Reficco.

Warner Bros. announced the series' development with Aguirre-Sacasa as showrunner in September 2020. It was given a straight-to-series order by HBO Max at the end of the same month. Filming took place in New York during the COVID-19 pandemic. It is the first series in the franchise not to be broadcast on ABC Family/Freeform and to be carried on a streaming television service.

The first season, titled Original Sin, premiered on July 28, 2022. In September 2022, the series was renewed for a second season, subtitled Summer School, that premiered on May 9, 2024. In September 2024, the series was canceled after two seasons.