|
| Christopher Reeve | … | Superman / Clark Kent |
| Gene Hackman | … | Lex Luthor / Nuclear Man (voice) |
| Jackie Cooper | … | Perry White |
| Marc McClure | … | Jimmy Olsen |
| Jon Cryer | … | Lenny |
| Sam Wanamaker | … | David Warfield |
| Mark Pillow | … | Nuclear Man |
| Mariel Hemingway | … | Lacy Warfield |
| Margot Kidder | … | Lois Lane |
| Damian McLawhorn | … | Jeremy |
| William Hootkins | … | Harry Howler |
| Jim Broadbent | … | Jean Pierre Dubois |
| Stanley Lebor | … | General Romoff |
| Don Fellows | … | Levon Hornsby |
| Robert Beatty | … | U.S. President |
| Bradley Lavelle | … | Tall Marshall (Chain Gang) |
| Mac McDonald | … | Marshall 1 |
| Czeslaw Grocholski | … | Russian General 1 |
| Steve Plytas | … | Russian General 2 |
| John Hollis | … | Russian General 3 (Kremlin) |
| Bob Sherman | … | Senator – Pentagon |
| Eiji Kusuhara | … | U.N. Guard – Japanese |
| Yuri Borienko | … | Russian General – Red Square |
| Boris Isarov | … | Cosmonaut Captain |
| Dorota Zieciowska | … | Cosmonaut (as Dorota Zienska) |
| Jirí Stanislav | … | Cosmonaut |
| Jayne Brook | … | Teacher – JFK High School |
| Ron Travis | … | Convict |
| Matthew Freeman | … | Submariner |
| Indira Joshi | … | Secretary General U.N. |
| Douglas W. Iles | … | Chief of Staff |
| Ted Maynard | … | Army Chief |
| Raymond Marlowe | … | Navy Chief |
| John Cagon | … | Technician |
| Malcolm Bullivant | … | U.N. Guard – Swedish |
| Mark Caven | … | Priest – Boystown |
| Diana Hunter | … | Museum Tour Guide |
| Nicholas Colicos | … | Paul – Metro Sports Club |
| Keith Edwards | … | Technician – Fort Mason |
| David Garth | … | First Elder |
| Esmond Knight | … | Second Elder |
| Eugene Lipinski | … | Cosmonaut – Space Walker |
| Dennis Creaghan | … | Bill Compton |
| Philip Fox | … | Husband – Great Wall of China |
| Jimmy Fung | … | Chinese Official – Great Wall of China |
| Guinevere John | … | Tourist – Great Wall of China |
| Peter Penry-Jones | … | Tourist – Great Wall of China |
| Witold Schejbal | … | Russian Premiere (as Witold Scheybal) |
| Rex Robinson | … | Engineer – Subway |
| Kerry Shale | … | MBC Newscaster |
| Susannah York | … | Lara (voice) |
| Rest of cast listed alphabetically: |
| Clive Mantle | … | Nuclear Man #2 (scenes deleted) |
| Max Bracey | … | Baby Superman (uncredited) (unconfirmed) |
| Kenneth Coombs | … | Reporter (uncredited) |
| Peter Diamond | … | S.W.A.T. team member with melting gun (uncredited) |
| Jill Goldston | … | Commuter (uncredited) |
| Christine Hewett | … | Woman Running for Bomb (uncredited) |
| Derek Lyons | … | Russian Guard (uncredited) |
| Paul Markham | … | Onlooker at Rally (uncredited) |
| Kingsley Pilgrim | … | School kid (uncredited) |
| Peter Roy | … | Policeman (uncredited) |
| Michael Ryan | … | Young Man, Metro Club (uncredited) |
| Tina Simmons | … | Commuter (uncredited) |
| Samantha Weysom | … | Lex Luther Girlfriend (uncredited) |
