Cillian Murphy

J. Robert Oppenheimer

Emily Blunt

Kitty Oppenheimer

Matt Damon

Leslie Groves

Robert Downey Jr.

Lewis Strauss

Alden Ehrenreich

Senate Aide

Scott Grimes

Counsel

Jason Clarke

Roger Robb

Kurt Koehler

Thomas Morgan

Tony Goldwyn

Gordon Gray

John Gowans

Ward Evans

Macon Blair

Lloyd Garrison

James D'Arcy

Patrick Blackett

Kenneth Branagh

Niels Bohr

Harry Groener

Senator McGee

Gregory Jbara

Chairman Magnuson

Ted King

Senator Bartlett

Tim DeKay

Senator Pastore

Steven Houska

Senator Scott