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Christopher Nolan’s Oppenheimer Biopic Cast and Their Real-Life Counterparts

The destroyer of worlds.

Cillian Murphy as Oppenheimer

Christopher Nolan’s twelfth film will be his second journey into the World War II era. In 2017’s Dunkirk, Nolan explored an epic true-story rescue during active wartime. His new film, however, focuses on the man who changed the course of the entire war: J. Robert Oppenheimer, the father of the atomic bomb. The script is based on the biography American Prometheus by Kai Bird and Martin J. Sherwin.

Much of the story takes place during the Manhattan Project, the government program that developed the atomic bomb. Oppenheimer examines a pivotal time in world history. Nolan enlisted a star-studded cast to play the historical figures, so here is the list of the known cast and their real-life counterparts.

Cillian Murphy as J. Robert Oppenheimer

Cillian Murphy as J. Robert Oppenheimer alongside a photo of the man himself.
(Universal Pictures,
Central Press / Stringer)

Playing the lead role of Oppenheimer is fan-favorite actor Cillian Murphy (Peaky Blinders, 28 Days Later). Prior to the Manhattan Project, Oppenheimer studied and taught physics. A brilliant scientist, he specialized in the theoretical and nuanced areas of his field. Asked to head the Manhattan Project, Oppenheimer worked with scientists and military officials to create the atomic bomb. In his private life, he donated to left-wing causes and anti-fascist movements. Although he never registered as a member of the Communist Party USA, he had many close ties to the organization, and this affiliation led to Oppenheimer’s post-war security hearing and removal of military clearance.

Emily Blunt as Katherine “Kitty” Oppenheimer

Emily Blunt in Mary Poppins Returns and Catherine Oppenheimer.
Washington Bureau / Staff)

Emily Blunt (A Quiet Place, Jungle Cruise) will play Oppenheimer’s wife. As a child, Kitty immigrated to America with her parents from Germany. A biologist and botanist, Kitty had a mind for science, and he also had very strong, left-wing views and was an active member of the Communist Party. Before meeting Oppenheimer, Kitty had been married several times. The two began their affair and married after she became pregnant with their first child. During the Manhattan Project, Kitty researched the dangers of radiation to the human body.

Matt Damon as Leslie Groves

Matt Damon and Leslie Groves.
(Jamie McCarthy/Getty Images for Deadline, MPI/Getty Images)

Departing from his usual roles, Matt Damon plays Lt. General Leslie Groves. Groves oversaw the building of the Pentagon before managing the Manhattan Project. In charge of picking laboratory sites and personnel, Groves backed Oppenheimer for the lead position. Many opposed Oppenheimer at the time for his lack of a Nobel Prize and ties to the Communist Party, but Groves, and his long military career, said Oppenheimer was the only man for the job.

Robert Downey Jr. as Lewis Strauss

Robert Downey Jr. as Tony Stark and Lewis Strauss.
(image: Marvel Entertainment,
J. Wilds / Stringer)

Robert Downey Jr. became a beloved household name after playing Tony Stark in the Iron Man/Avengers films. Because of that, it may be hard to see him in a historical drama. Lewis Strauss started his career as an investment banker and philanthropist. Eventually, he became a founding member of the U.S. Atomic Energy Commission. Strauss and Oppenheimer clashed over personal and professional topics, and many people blame Strauss for triggering the hearing that stripped Oppenheimer of security clearance.

Florence Pugh as Jean Tatlock

Yelena Belova in Black Widow
(Marvel Entertainment)

Before Oppenheimer married Kitty (and some say after), he had a long affair with Jean Tatlock. A psychiatrist and physician, Jean was also a member of the Communist Party. She frequently reported for their newspaper, Western Worker. The amazing and talented Florence Pugh (Black Widow, Little Women) will play Jean.

Dylan Arnold as Frank Oppenheimer

Dylan Arnold as Theo in Netflix's You.
(John P. Fleenor/Netflix)

Robert Oppenheimer’s brother Frank (played by Dylan Arnold) also worked on the Manhattan Project. As a physicist, he had many major achievements throughout his life. He pushed for the peaceful use of nuclear technology. After the war, he helped develop the proton linear accelerator, but Frank Oppenheimer struggled to find work once his Communist Party allegiance become known. Later in life, he founded the Exploratorium in San Francisco.

Rounding out the scientific team is Edward Teller (Benny Safdie), Ernest Lawrence (Josh Hartnett), and Robert Serber (Michael Angarano).

In addition, there is a slew of well-known, award-winning actors cast without roles officially attached. Kenneth Branagh and Rami Malek top that list. They are followed by David Krumholtz, Jack Quaid, Matthew Modine, Alden Ehrenreich, and Dane DeHaan.

Universal Pictures slated Oppenheimer for theatrical release on July 21, 2023. As a history nerd, I will be counting down the days.

(featured image: Universal Pictures)

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D.R. Medlen (she/her) is a freelance pop culture writer at The Mary Sue. After finishing her BA in History, she finally pursued her lifelong dream of being a full-time writer in 2019. She expertly fangirls over Marvel, Star Wars, and historical fantasy novels (the spicier the better). When she's not writing or reading, she lives that hobbit-core life in California with her spouse, offspring, and animal familiars.