Exploring the brilliant mind responsible for the creation of the atomic bomb, Christopher Nolan’s biographical thriller Oppenheimer boasts an extraordinary ensemble cast led by Cillian Murphy in the titular role. Alongside key roles played by Robert Downey Jr., Florence Pugh, Matt Damon and Emily Blunt, the film has an impressive lineup of cameos, and quite a few of them are by Oscar-winning actors.

Gary Oldman

In a surprising appearance, Oscar winner Gary Oldman — famous for his role as Commissioner Jim Gordon in Nolan’s The Dark Knight trilogy — plays Harry S. Truman, the 33rd President of the United States, in Oppenheimer. Truman tries to bring Oppenheimer on board his hydrogen bomb project. However, as the physicist declines on moral grounds, Truman summarily dismisses him and asks his aide not to allow “the crybaby” near him in future.

Casey Affleck

Another Oscar winner, Casey Affleck, takes on the role of Boris Pash, the chief of army counter-intelligence at the Presidio in San Francisco. Affleck displays the cold brutality of Pash during a brief interrogation scene in which Pash questions Oppenheimer about the possible leak of confidential information to the Russians during World War II.

Rami Malek

Rami Malek portrays David Hill, an associate experimental physicist. Malek, who won an Oscar for his remarkable portrayal of Freddie Mercury in Bohemian Rhapsody, feels wasted in this role. He has only one notable scene where Hill exposes Strauss’ machinations to discredit Oppenheimer during a Senate committee meeting.

Kenneth Branagh

Kenneth Branagh slips into the role of Niels Bohr, the Nobel Prize-winning physicist admired by Oppenheimer and his contemporaries for his groundbreaking work on the atomic structure. In his brief appearance in the movie, Bohr cautions Oppenheimer about the dangers of unbridled technology.

Benny Safdie

Licorice Pizza actor Benny Safdie is Edward Teller, a theoretical physicist who collaborated with Oppenheimer on the Manhattan Project. Teller is known as ‘the father of the hydrogen bomb’. Once a trusted aide, Teller develops bitterness towards Oppenheimer when the latter publicly voices his concerns about the hydrogen bomb. Teller then collaborates with Lewis Strauss (Robert Downey Jr.) to bring Oppenheimer down.

David Krumholtz

Comedian David Krumholtz plays Isidor Isaac Rabi, a Nobel Prize-winning physicist who served as a consultant on the Manhattan Project. Rabi is a confidante and friend of Oppenheimer. He is calmer, more mature and displays wisdom and compassion, as opposed to the unpredictable and finicky Oppenheimer.

Tom Conti

The role of the iconic and influential scientist Albert Einstein has gone to Tom Conti, who has three very brief appearances in the movie, every time cautioning Oppenheimer about his ambitious project.

Alden Ehrenreich

Alden Ehrenreich makes a brief but impactful cameo as a Senate aide to Strauss in Oppenheimer. Ehrenreich, known for his role in Hail Caesar, acts as a voice of conscience and shows Strauss the mirror when he learns about the latter’s subterfuge.

Emma Dumont

Licorice Pizza actress Emma Dumont plays Oppenheimer’s sister-in-law Jackie, portrayed as an active supporter of the Communist Party who tried to recruit Oppenheimer in her cause.

Flora Nolan

Christopher Nolan’s daughter Flora Nolan has a brief role in the film as a character whose face is blown off by a nuclear explosion. Her appearance comes at a critical juncture when Oppenheimer is going through an ethical crisis after the bombings in Hiroshima and Nagasaki.