Christopher Nolan's Oppenheimer set to add Josh Hartnett to all-star cast

Christopher Nolan has put together some incredible casts in its career, but his new Oppenheimer movie is set to top the lot – and it’s growing bigger by the day.

As per Deadline, Penny Dreadful actor Josh Hartnett – also known for his turns in Pearl Harbor and Black Hawk Down – is set to join the ensemble cast in an undisclosed role.

Oppenheimer, Nolan’s first Universal movie, is already bringing out the big guns in terms of its major players. Cillian Murphy and Emily Blunt first signed up as J. Robert Oppenheimer, the man who developed the atom bomb, and his wife Katherine respectively.

From there, Matt Damon and Robert Downey Jr. joined in as-yet-unannounced roles, while Florence Pugh, Rami Malek, and Benny Safdie also came on-board at a later date.

Oppenheimer is set to be based on the true-life story of Oppenheimer and the book that charted those events, American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer by Kai Bird and Martin J. Sherwin.

Nolan’s most recent movie, Tenet, was one of the first major post-COVID releases in August 2020. Despite its middling box office returns, it was Nolan’s response to HBO Max’s decision to go day-and-date with movie releases on streaming that caused the most ripples in Hollywood.

"Some of our industry’s biggest filmmakers and most important movie stars went to bed the night before thinking they were working for the greatest movie studio and woke up to find out they were working for the worst streaming service," Nolan told The Hollywood Reporter at the time.

Oppenheimer is set for release on July 21, 2023. For more on what’s coming to cinemas, check out our guide to movie release dates.