| Person | Type | Job | Role(s) |
|---|---|---|---|
 Bruce Robinson | Crew | Writing | Screenplay |
 Ennio Morricone | Crew | Sound | Music |
 Françoise Bonnot | Crew | Editing | Editor |
 Monty Westmore | Crew | Costume & Make-Up | Makeup Designer |
Nancy Foy | Crew | Production | Casting |
 Roland Joffé | Crew | Writing | Screenplay, Director |
Tony Garnett | Crew | Production | Producer |
 Vilmos Zsigmond | Crew | Camera | Director of Photography |
 Alan Oppenheimer | Cast | Actor | (voice) |
 Allan Corduner | Cast | Actor | Franz Goethe |
 Arthur Holden | Cast | Actor | Oakridge Doctor |
Barry Yourgrau | Cast | Actor | Edward Teller |
Bill Rubenstein | Cast | Actor | Times Reporter |
 Bonnie Bedelia | Cast | Actress | Kitty Oppenheimer |
 Clark Gregg | Cast | Actor | Douglas Panton |
 Del Close | Cast | Actor | Dr. Kenneth Whiteside |
Don Pugsley | Cast | Actor | Bronston |
 Dwight Schultz | Cast | Actor | J. Robert Oppenheimer |
 Ed Lauter | Cast | Actor | Whitney Ashbridge |
 Fred Thompson | Cast | Actor | Melrose Hayden Barry |
Gerald Hiken | Cast | Actor | Leo Szilard |
 James Eckhouse | Cast | Actor | Robert Harper |
 Jim True-Frost | Cast | Actor | Donald Hornig |
Joe D'Angerio | Cast | Actor | Seth Neddermeyer |
 John C. McGinley | Cast | Actor | Richard Schoenfield |
 John Considine | Cast | Actor | Robert Tuckson |
 John Cusack | Cast | Actor | Michael Merriman |
 Jon DeVries | Cast | Actor | Johnny Mount |
 Krzysztof Pieczyński | Cast | Actor | Otto Frisch |
 Laura Dern | Cast | Actress | Kathleen Robinson |
 Logan Ramsey | Cast | Actor | Brehon Somervell |
 Madison Mason | Cast | Actor | Boris Pash |
 Mary Pat Gleason | Cast | Actress | Dora Welsh |
 Matthew Faison | Cast | Actor | (voice) |
Michael Brockman | Cast | Actor | William "Deke" Parsons |
 Natasha Richardson | Cast | Actress | Jean Tatlock |
 Paul Newman | Cast | Actor | Gen. Leslie R. Groves |
 Péter Halász | Cast | Actor | George Kistiakowsky |
Ron Frazier | Cast | Actor | Peter de Silva |
 Ron Vawter | Cast | Actor | Jamie Latrobe |
 Stan Jones | Cast | Actor | (voice) |
Steven Baigelman | Cast | Actor | Dr. Avenell |
 Todd Field | Cast | Actor | Robert Wilson |
Walker Edmiston | Cast | Actor | (voice) |
 Robert Peter Gale | Cast | Actor | Dr. Louis Hempelman |
Walter Sullivan | Cast | Henry Stimson | |
 Ken Strausbaugh | Cast | Observation Officer | |
Donald MacKechnie | Cast | Actor | James Tuck |
David Politzer | Cast | Robert Serber | |
Marek Alboszta | Cast | Scientist | |
Brian Wandell | Cast | Dennis Talmudge | |
Frank Benettieri Jr. | Cast | Messenger | |
Brent Harrison | Cast | Peter Oppenheimer | |
David C. Parnes | Cast | Raincoat Man | |
John Williams | Cast | Mack Stoddard | |
Allen Poirson | Cast | Harold McDonald | |
Tom McFarlane | Cast | Scientist | |
Franco Cutietta | Cast | Enrico Fermi | |
Wesley Harrison | Cast | Peter Oppenheimer | |
Roger Cubicciotti | Cast | Frank Oppenheimer | |
| Person | Type | Job | Role(s) |
