Näyttelijät

• Cillian Murphy — J. Robert Oppenheimer
• Matt Damon — Lt. Gen. Leslie Groves
• Emily Blunt — Katherine 'Kitty' Vissering Oppenheimer
• Robert Downey Jr. — Lewis Strauss
• Josh Hartnett — Ernest Lawrence
• Florence Pugh — Jean Tatlock
• Rami Malek — David Hill
• Benny Safdie — Edward Teller
• Jack Quaid — Richard Feynman
• Guy Burnet — George Eltenton
• Danny Deferrari — Enrico Fermi
• Gary Oldman — Harry S. Truman
• Dane DeHaan — Kenneth Nichols
• Matthew Modine — Vannevar Bush
• Dylan Arnold — Frank Oppenheimer
• Alden Ehrenreich — Senate aide
• David Krumholtz — Isidor Isaac Rabi
• Kenneth Branagh — Niels Bohr
• David Dastmalchian — William L. Borden
• Jason Clarke — Roger Robb
• Louise Lombard — Ruth Tolman
• Scott Grimes — Counsel
• Christopher Denham — Klaus Fuchs
• James D'Arcy — Patrick Blackett
• Josh Peck — Kenneth Bainbridge
• Gustaf Skarsgård — Hans Bethe
• Casey Affleck — Boris Pash
• Tom Conti — Albert Einstein
• Matthias Schweighöfer — Werner Heisenberg