Pretty Little Liars is an American slasher teen drama mystery television series created by Roberto Aguirre-Sacasa and Lindsay Calhoon Bring for Max.

[2] The series features an ensemble cast, headed by Bailee Madison, Chandler Kinney, Zaria, Malia Pyles, and Maia Reficco.

[8] On September 2, 2020, it was announced that a new Pretty Little Liars series was in development at Warner Bros., with Riverdale creator Roberto Aguirre-Sacasa taking over as showrunner from I. Marlene King.

[16] Original Sin takes place within the same continuity as the previous television series, but follows new characters and storylines in a new setting.

[19][20] On September 7, 2022, HBO Max renewed the series for a second season, retitled as Pretty Little Liars: Summer School.

[21][22] In August 2021, Zaria, Malia Pyles, Alex Aiono, Mallory Bechtel, and Eric Johnson joined the main cast.

[23][24] In September 2021, Carson Rowland, Jordan Gonzalez, Ben Cook, Elias Kacavas, Benton Greene, Lea Salonga, Sharon Leal, Carly Pope, Elena Goode, and Zakiya Young were cast in recurring roles.

[25][26] In November 2021, Cristala Carter, Derek Klena, Kate Jennings Grant, Robert Stanton, Jennifer Ferrin, Lilla Crawford, Brian Altemus, Anthony Ordonez, and Jeffrey Bean joined the cast in recurring capacities.

[34] However, after a deal was reached on September 27, along with the actors strike on November 9, filming for the second season resumed later that same month and wrapped on December 8, 2023.

The website's critics consensus reads, "Boasting a tantalizing new mystery along with a refreshingly grounded crop of pretty little liars, Original Sin is a gossipy good time.