Oppenheimer

Adam Kroeger

Army Captain

Alden Ehrenreich

Senate Aide

Alex Wolff

Luis Alvarez

Benny Safdie

Edward Teller

Brett DelBuono

Concerned Scientist

Britt Kyle

Barbara Chevalier

Bryce Johnson

AAF Officer 2

Casey Affleck

Boris Pash

Christina Hogue

Kissing Woman

Christopher Denham

Klaus Fuchs

Cillian Murphy

J. Robert Oppenheimer

Dane DeHaan

Kenneth Nichols

Danny Deferrari

Enrico Fermi

David Dastmalchian

William Borden

David Krumholtz

Isidor Rabi

David Rysdahl

Donald Hornig

Devon Bostick

Seth Neddermeyer

Drew Kenney

Soldier

Dylan Arnold

Frank Oppenheimer

Emily Blunt

Kitty Oppenheimer

Emma Dumont

Jackie Oppenheimer

Flora Nolan

Burn Victim

Florence Pugh

Jean Tatlock

Gary Oldman

Harry Truman

Gregory Jbara

Chairman Magnuson

Gustaf Skarsgård

Hans Bethe

Guy Burnet

George Eltenton

Hap Lawrence

Lyndon Johnson

Harrison Sloan Gilbertson

Philip Morrison

Harry Groener

Senator McGee

Jack Cutmore-Scott

Lyall Johnson

Jack Quaid

Richard Feynman

James D'Arcy

Patrick Blackett

James Remar

Henry Stimson

James Urbaniak

Kurt Gödel

Jason Clarke

Roger Robb

Jefferson Hall

Haakon Chevalier

Jeff Hephner

Congressman

Jeremy John Wells

AAF Officer

Jessica Erin Martin

Charlotte Serber

John Gowans

Ward Evans

Josh Hartnett

Ernest Lawrence

Josh Peck

Kenneth Bainbridge

Josh Zuckerman

Rossi Lomanitz

Kate French

Presidential Aide

Kenneth Branagh

Niels Bohr

Kerry Westcott

Laughing Woman

Kurt Koehler

Thomas Morgan

Louise Lombard

Ruth Tolman

Macon Blair

Lloyd Garrison

Maria Teresa Zuppetta

Consoling Woman

Máté Haumann

Leo Szilard

Matt Damon

Leslie Groves

Matthew Modine

Vannevar Bush

Matthias Schweighöfer

Werner Heisenberg

Meg Schimelpfenig

Senator's Assistant (uncredited)

Michael Andrew Baker

Joe Volpe

Michael Angarano

Robert Serber

Olivia Thirlby

Lilli Hornig

Olli Haaskivi

Edward Condon

Pat Skipper

James Byrnes

Petrie Willink

Dutch Student

Rami Malek

David Hill

Robert Downey Jr.

Lewis Strauss

Ronald Auguste

J. Ernest Wilkins

Rory Keane

Hartland Snyder

Sadie Stratton

Mary Washburn

Scott Grimes

Counsel

Sean Avery

Weatherman

Steve Coulter

James Conant

Steven Houska

Senator Scott

Ted King

Senator Bartlett

Tim DeKay

Senator Pastore

Tom Conti

Albert Einstein

Tom Jenkins

Richard Tolman

Tony Goldwyn

Gordon Gray

Trond Fausa

George Kistiakowsky

Tyler Beardsley

Weeping Man

Will Roberts

George C. Marshall