 | Robert Ryan als Captain Nemo |
 | Chuck Connors als Senator Robert Fraser |
 | Nanette Newman als Helena Beckett |
 | Luciana Paluzzi als Mala |
 | John Turner als Joab |
 | Bill Fraser als Barnaby Bath |
 | Kenneth Connor als Swallow Bath |
 | Allan Cuthbertson als Lomax |
 | Christopher Hartstone als Phillip Beckett |
| Ian Ramsey als Adam |
| John Moore als Skipper |
| Anthony Bailey als Sailor |
| Alan Barry als Sailor |
| Vincent Harding als Mate Navigator |
| James Hill | Director |
| Pip Baker | Writer |
| R. Wright Campbell | Writer |
| Jane Baker | Writer |
| Reg Bream | Assistant Art Director |
| Jules Verne | Characters |
| Bertram Ostrer | Producer |
| Steven Pallos | Executive Producer |
| Angela Morley | Original Music Composer |
| Alan Hume | Director of Photography |
| Bill Lewthwaite | Editor |
| Irene Howard | Casting |
| William C. Andrews | Art Direction |
| Hazel Peiser | Set Decoration |
| Olga Lehmann | Costume Design |
| Ernest Gasser | Makeup Artist |
| Alice Holmes | Hairstylist |
| Albert Becket | Production Supervisor |
| Terry Lens | Production Manager |
| Ted Lewis | Assistant Director |
| Raymond Becket | Third Assistant Director |
| Paddy Carpenter | Second Assistant Director |
| Peter Sheilds | Draughtsman |
| Brian Muir | Sculptor |
| Cyril Swern | Sound |
| A.W. Watkins | Sound Supervisor |
| Jim Sibley | Sound Editor |
| Bob Jones | Sound Mixer |
| Richard Conway | Special Effects |
| George Gibbs | Special Effects |
| Jack Mills | Special Effects |
| Fritz Ford | Stunts |
| Joe Dunne | Stunt Coordinator |
| Cyd Child | Stunts |
