Oppenheimer (ˈɒpənhaɪmər ) is a 2023 epic biographical thriller film written and directed by Christopher Nolan. Based on the 2005 biography American Prometheus by Kai Bird and Martin J. Sherwin, the film chronicles the career of American theoretical physicist J. Robert Oppenheimer. The story predominantly focuses on Oppenheimer's studies, his direction of the Manhattan Project during World War II, and his eventual fall from grace due to his 1954 security hearing. The film stars Cillian Murphy as the title character, Emily Blunt as his wife, "Kitty", Matt Damon as head of the Manhattan Project Leslie Groves, Robert Downey Jr. as U.S. Atomic Energy Commission member Lewis Strauss, and Florence Pugh as Communist Party USA member Jean Tatlock. The ensemble supporting cast includes Josh Hartnett, Casey Affleck, Rami Malek, and Kenneth Branagh.
The film was announced in September 2021 after Universal Pictures won a bidding war for Nolan's screenplay, following Nolan's conflict with longtime distributor Warner Bros. Murphy was the first cast member to sign on the following month, with the rest of the cast joining between November 2021 and April 2022. Pre-production was under way by January 2022, and filming took place from February to May. Oppenheimer was filmed in a combination of IMAX 65 mm and 65 mm large-format film, including, for the first time in history, sections in IMAX black-and-white film photography. Like his previous works, Nolan used extensive practical effects and minimal . Oppenheimer is Nolan's first film to receive an R-rating in the United States since Insomnia in 2002.
Oppenheimer premiered at Le Grand Rex in Paris on July 11, 2023, and was theatrically released in the United States and United Kingdom on July 21 by Universal. Its simultaneous release with Warner Bros.' Barbie led to the "Barbenheimer" cultural phenomenon, which encouraged audiences to see both films as a double feature.