See the Stars in 'Oppenheimer' Compared to the Historical Figures They Play (2024)

Cillian Murphy as J. Robert Oppenheimer

Cillian Murphy plays the titular theoretical physicist in Christopher Nolan's long-awaited flick. Speaking to the Associated Press back in May, Murphy opened up about playing the man remembered as the "father of the atomic bomb." He called the role "a huge responsibility" since Oppenheimer "was complicated and contradictory and so iconic."

Murphy endured physical and mental challenges as he prepared for the part. He told The New York Times about how he lost "quite a bit of weight" to appear as Oppenheimer did. "He was very slim," said the Irish actor. "Almost emaciated."

In conversation with The Guardian, Murphy explained that his extreme diet affected his behavior, too. "I was running on crazy energy; I went over a threshold to where I was not worrying about food or anything," he said. "I was so in it, a state of hyper something. But it was good because the character was like that. He never ate.”

Emily Blunt as Katherine "Kitty" Oppenheimer

Oppenheimer's wife is portrayed by Emily Blunt. The biologist moved to Los Alamos, New Mexico with her husband in 1943, while he was working on the Manhattan Project. As Oppenheimer covertly developed the nuclear weapons, Kitty worked with a physician to assess the danger presented by radiation.

Blunt spoke to PEOPLE about her relationship with her on-screen husband just a month before the film's premiere in mid-July.

"Me and Cillian are like thick as thieves because we worked together before [onA Quiet Place Part II] and I adore him," she said. "We have a lot of trust between us. So I spent the most time with Cillian.”

Matt Damon as Leslie Groves

Matt Damon plays Lieutenant General Leslie Groves in the historical drama. During World War II, the Army Corps of Engineers officer worked on the Pentagon's construction before directing the Manhattan Project.

Damon recently expressed his excitement about working with Christopher Nolan again in an interview with Entertainment Weekly, and how his passion for the director cuts deep into his personal life. Damon shared that he promised his wife, Luciana, that he'd take time off work unless Nolan offered him a role.

"This is without knowing whether or not he was working on anything, because he never tells you,” added the actor, who also appeared in Nolan's 2014 space drama Interstellar. “He just calls you out of the blue. And so, it was a moment in my household."

Robert Downey Jr. as Lewis Strauss

Atomic Energy Commission chairman Lewis Strauss — played by Robert Downey Jr. — worked closely with Oppenheimer during the development of nuclear weapons. However their differing political and ideological values led to high tensions between the two figures. Strauss suspected the physicist was allied with communist forces and requested that the FBI investigate further. This resulted in months of court hearings about Oppenheimer's actions and background and, ultimately, his top-security clearance was revoked.

While Downey's character had more than a few qualms about Oppenheimer's story, the actor himself feels the complete opposite. Deadline shared a video of the star praising the film at its London premiere.

“Just going to flat out say it: This is the best film I’ve ever been in," Downey says in the clip. “I cannot wait for you all to experience it.”

Florence Pugh as Jean Tatlock

Florence Pugh plays Oppenheimer's mistress, Jean Tatlock. Her associations with the Communist Party placed the physicist in a precarious position during the investigations of his political affiliations.

The Midsommar actress also expressed her appreciation for Nolan's casting her in the film. Pugh complimented his directing approach while speaking to the Radio Times.

"When I walked on set, I couldn't believe there was that similar, incredible adrenaline, which I hadn't felt on a massive movie for a long time," she said. "It's a wonderful thing to inject into a film set — believing in yourself and what you're making."

Josh Hartnett as Ernest Lawrence

The war drama features Josh Hartnett as Ernest Lawrence, a Nobel Prize-winning physicist who played a key role in the Manhattan Project.

Casey Affleck as Boris Pash

Casey Affleck plays a military intelligence officer tasked with interrogating Oppenheimer and others about their possible affiliations with the Communist Party. Boris Pash eventually concluded that the Manhattan Project leader wasn't a spy, and should remain a part of the nuclear development efforts.

Kenneth Branagh as Niels Bohr

Kenneth Branagh plays one of quantum physics' most foundational minds, Niels Bohr. During World War II, Bohr supported the efforts of Robert Oppenheimer and his colleagues working on the Manhattan Project. Bohr was a promoter of scientific progress and his hopes for nuclear development aligned with Oppenheimer's, despite the impact both knew it would have on international affairs.

Benny Safdie as Edward Teller

Edward Teller, played by Benny Safdie in Christopher Nolan's epic war drama, was the only member of the scientific community to testify against Oppenheimer at his security clearance hearings.

Safdie's Oppenheimer role is his biggest to date. Speaking to GQ, Nolan said that he cast the actor after seeing him in Good Time (which Safdie directed with his brother) and in Paul Thomas Anderson's 2021 indie film, Licorice Pizza.

"I called Paul [Thomas Anderson] and I asked about Benny," Nolan recalled. "And he gave him the strongest possible endorsem*nt and pointed out that he's an incredible actor, but also just a wonderful guy."

Dylan Arnold as Frank Oppenheimer

Fans will probably recognize Arnold as Love Quinn's boy toy in Netflix's You and the actor continues to flex his drama skills playing Frank Oppenheimer in the Nolan epic.

Much like his older brother, Frank was a talented scientist who earned a degree in physics from Johns Hopkins University before later getting his Ph.D. from the California Institute of Technology, where he studied artificially induced radiation.

He joined the Manhattan Project in 1945 and became a professor after the war. A devout lover of science, Frank founded the Exploratorium — a museum of science, technology and arts — in 1969.

Gary Oldman as President Harry S. Truman

Gary Oldman and Christopher Nolan reunite once more. Because the two haven't worked together since they collaborated on the Batman trilogy, fans were excited to hear they're working together again, though Oldman appears in only one scene in the film.

The veteran actor plays President Truman, who ordered the atomic bomb be used in the bombings of Hiroshima and Nagasaki during WWII.

Jason Clarke as Roger Robb

Playing U.S. attorney Roger Robb is Jason Clarke. Robb was selected to prosecute Oppenheimer's security clearance hearing in 1954.

"What I was reminded of with the whole story of [Oppenheimer] ... is that we really don't know all of the benefits and the cost of what this man, this group and his leadership have done for this planet," Clarke reflected while at the Paris premiere of the film. "The story is still going to play out. I truly believe that."