With all its prestige, it’s hard to think of a greater movie for an actor to be cast in thanOppenheimer, even if it’s a relatively small part, like Jackie Oppenheimer. Christopher Nolan’s three-hour, R-rated historical epic about the making of the atomic bomb was a box-office juggernaut in 2023, raking in nearly $1 billion worldwide. Winning seven awards at the 2024 Oscars,Oppenheimernotably took home the coveted Best Picturewhile Nolan picked up his first Academy Award for Best Director. Though nominating every great acting performance would be impossible, Cillian Murphy and Robert Downey Jr. won for theirs.

BecauseOppenheimerhas such an extensive cast, it was sometimes difficult for the supporting parts to get a lot of screen time. This is true for talented actors like future Superman, David Dastmalchian, Dane DeHaan, Alex Wolff, and Emma Dumont, who briefly played Jackie Oppenheimer. Though she isn’t explored in much detail during the film, Jackie Oppenheimer was her own person, and Emma Dumont made a name for themselves before being cast as the character inOppenheimer.

Oppenheimer greeting Jackie

Jackie Oppenheimer Was J. Robert Oppenheimer’s Sister-In-Law

Oppenheimer Did Not Approve Of His Brother Marrying Jackie

Jaquenette Yvonne “Jackie” Oppenheimer was an active member of the Young Communist League while studying at the University of California, Berkeley. She met Frank Oppenheimer, younger brother to J. Robert Oppenheimer, during her college days and eventually married him in 1936. Both Frank and Jackie joined theAmerican Communist Party against the advice of J. Robert Oppenheimer. In fact,Oppenheimer didn’t approve of his brother marrying Jackie at all, partly because of her Communist ties, and he also believed both Frank and Jackie to be immature.

Robert Downey Jr.’s Oppenheimer Character Explained (& What The Actor’s Said About His Oscar-Winning Role)

Oppenheimer was considered one of the best movies of 2023, with Robert Downey Jr.’s Oscar-winning performance a particular highlight of the film.

Though Jackie only has one scene inOppenheimer, it perfectly depicts the attitude Oppenheimer had towards her. Their interactions during the film happen at the Communist fundraising party where Frank briefly reintroduces her to J. Robert Oppenheimer only for him to half-heartedly greet her. Once inside,he introduces his brother and Jackie, forgetting her name entirely. It’s not the most pivotal scene in the film, but it is just another look into various ways Oppenheimer interacted with others.

Lewis Strauss (Robert Downey Jr) looking concerned in Oppenheimer

Where You’ve Seen Jackie Oppenheimer Actor Emma Dumont

Dumont Notably Appeared In The X-Men Series, The Gifted

Prior to being cast as Jackie Oppenheimer, Emma Dumont acted in a variety of movies and television for over a decade. Their notable roles include Melanie Sagal inBun Heads,which ran for 18 episodes on ABC Family from 2012-2013, and Emma Karn inAquarius.Dumont also had small roles in films by prestigious directors, including Paul Thomas Anderson’sInherent ViceandLicorice Pizza.

Their very first role was in the 2009 filmTrue Adolescents, starring Mark Duplass. In December 2024,Emma Dumont came out as non-binary, using they/them pronouns and going by Nick Dumont in their personal life, though Emma Dumont is still their stage name.

Emma Dumont and Dylan Arnold in Oppenheimer

Oppenheimer

Jackie Oppenheimer

Dumont’s role inThe Giftedis probably their most famous.The Giftedwas a superhero television series based on Marvel’s X-Men, though it was not connected to the FoxX-Menfranchise at the time, staying within its own universe where the X-Men disappeared.The Giftedwas canceled after two seasons. Emma Dumont played Polaris in the show, the daughter of Magneto, arguably the most important Marvel Comics villain of all time. Though not much is known beyond the cast and crew,IMDBhas Emma Dumont listed in a starring role in the unscheduled thriller,New Me.

Was Jackie’s Depiction Accurate?

How accurate Jackie Oppenheimer is in Christopher Nolan’sOppenheimeris a little tricky, given how little screen time she has, and the fact that she is used mostly to show J. Robert Oppenheimer’s frankly indifferent view towards her.Though it is a slightly fictionalized story of the events at the time, Jackie Oppenheimer was indeed a member of the Communist Party, joining in 1938 against the advice of J. Robert Oppenheimer, the brother of her husband, Frank.

“You Really Impressed Me”: An Oppenheimer Actor Thought He Was A “Glorified Extra”, But Then Christopher Nolan Complimented Him In Front Of The Whole Cast

An Oppenheimer star who plays a relatively minor role was surprised when Christopher Nolan singled him out with an unusual compliment during filming.

The relationship, or lack thereof, between J. Robert Oppenheimer and Jackie also feels accurate to what was known about how he felt about Frank marrying Jackie as well as their involvement with the Communist Party.Oppenheimeris still a biopic and not a documentary, though, which means it isn’t 100% accurate to essentially anybody portrayed in it, as Christopher Nolan added the right dramatic flair to really elevate the entire movie.

Oppenheimer triumphantly raising his hat to a cheering crowd while the American flag waves behind him

Cast

Oppenheimer is a film by Christopher Nolan, which follows the theoretical physicist J. Robert Oppenheimer, the man behind the atomic bomb. Cillian Murphy will play the titular role, with the story based on the book American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer by Kai Bird and Martin J. Sherwin.

Oppenheimer Poster