Matt Damon Leslie Groves
Gary Oldman Harry Truman
Emily Blunt Kitty Oppenheimer
Florence Pugh Jean Tatlock
Robert Downey Jr. Lewis Strauss
Cillian Murphy J. Robert Oppenheimer
Christopher Nolan Director, Producer, Writer
James Remar Henry Stimson
Rami Malek David Hill
Jack Quaid Richard Feynman
Devon Bostick Seth Neddermeyer
Petrie Willink Dutch Student
Dane DeHaan Kenneth Nichols
Gustaf Skarsgård Hans Bethe
James Woods Executive Producer
Will Roberts George C. Marshall
Casey Affleck Boris Pash
James D'Arcy Patrick Blackett
Matthias Schweighöfer Werner Heisenberg
Kenneth Branagh Niels Bohr
Tony Goldwyn Gordon Gray
Josh Hartnett Ernest Lawrence
Richard Molloy Additional Second Assistant Director
Jason Clarke Roger Robb
David Dastmalchian William Borden
Patrick D. Baker Driver
Olivia Thirlby Lilli Hornig
Alden Ehrenreich Senate Aide
Matthew Modine Vannevar Bush
Bryce Johnson AAF Officer 2
Nick Ellsberg First Assistant Editor
Scott Grimes Counsel
Máté Haumann Leo Szilard
Danny Downey Stunts
Steve Coulter James Conant
Alex Wolff Luis Alvarez
David Krumholtz Isidor Rabi
Benny Safdie Edward Teller
Mallory Bradley Costumer
Duffy Gaver Stunts
Louise Lombard Ruth Tolman
Alex Gibson Sound Effects Editor
Steve DeCastro Stunts
Michael Angarano Robert Serber
David Rysdahl Donald Hornig
Taylor Estevez Propmaker
Guy Burnet George Eltenton
Jason Gary Best Boy Grip
Macon Blair Lloyd Garrison
Terry Jackson Stunts
Emma Thomas Producer
Dylan Arnold Frank Oppenheimer
Emma Dumont Jackie Oppenheimer
Eric Luling On Set Dresser
Kelly A. Cook Still Photographer
Josh Zuckerman Rossi Lomanitz
Michael Andrew Baker Joe Volpe
Jaron Whitfill Camera Technician
Josh Peck Kenneth Bainbridge
Jeff Hephner Congressman
Tom Conti Albert Einstein
Flora Nolan Burn Victim
Tim DeKay Senator Pastore
Jason Hamer Prosthetic Designer
Harrison Gilbertson Philip Morrison
Andrew Stahl Second Assistant Director
Kerry Westcott Laughing Woman
Jefferson Hall Haakon Chevalier
Trond Fausa Aurvåg George Kistiakowsky
John Gowans Ward Evans
George Cottle Stunt Coordinator
Steve Gehrke Script Supervisor