I Know What You Did Last Summer is a 2025 American slasher film that is the fourth installment in the I Know What You Did Last Summer franchise and a sequel to I Still Know What You Did Last Summer (1998). The film takes place 27 years after the Tower Bay murders in the second film, when another hook-wielding killer appears and begins targeting a group of friends one year after they covered up a car crash in which they killed someone. It was directed by Jennifer Kaytin Robinson, who co-wrote the screenplay with Sam Lansky from a story by Leah McKendrick and Robinson. The film stars Madelyn Cline, Chase Sui Wonders, Jonah Hauer-King, Tyriq Withers, Sarah Pidgeon, Billy Campbell, Gabbriette Bechtel, and Austin Nichols, with Freddie Prinze Jr., and Jennifer Love Hewitt reprising their roles as Ray Bronson and Julie James from the first two films. Plans for a fourth film in the franchise started in 2014, when Mike Flanagan and Jeff Howard signed on to write a reboot with no connection to the previous installments. However, this version was ultimately not produced. Following the cancellation of the 2021 television series adaptation, the project was relaunched when Robinson pitched her version to Sony Pictures. The film was put into early development in February 2023, with producer Neal H. Moritz returning. Prinze Jr. and Hewitt were confirmed to be returning in 2024, with the new cast members joining throughout the year. Filming took place between October 2024 and March 2025 in Sydney and Los Angeles. I Know What You Did Last Summer premiered at the United Theater on Broadway in Los Angeles on July 14, 2025, and was theatrically released by Sony Pictures Releasing through its Columbia Pictures and Screen Gems labels in the United States on July 18. The film received mixed reviews from critics and grossed $64.8 million worldwide.