| Richard Harris | Oliver Cromwell |
| Alec Guinness | Charles I |
| Robert Morley | Earl of Manchester |
| Dorothy Tutin | Queen Henrietta Maria |
| Frank Finlay | John Carter |
| Timothy Dalton | Prince Rupert |
| Charles Gray | The Earl of Essex |
| Michael Jayston | Henry Ireton |
| Patrick Wymark | Earl of Strafford |
| Patrick Magee | Hugh Peters |
| Nigel Stock | Sir Edward Hyde |
| Richard Cornish | Oliver Cromwell |
| Anna Cropper | Ruth Carter |
| Michael Goodliffe | Solicitor General |
| Jack Gwyllim | General Byron |
| Basil Henson | Hacker |
| Patrick Holt | Capt. Lundsford |
| Stratford Johns | President Bradshaw |
| Geoffrey Keen | John Pym |
| Anthony May | Richard Cromwell |
| Ian McCullough | John Hampden |
| John Paul | Gen. Digby |
| Llewellyn Rees | The Speaker |
| Robin Stewart | Prince of Wales |
| Andre Van Gyseghem | Archbishop Riniuccini |
| Zena Walker | Mrs. Cromwell |
| Douglas Wilmer | Thomas Fairfax |
| Anthony Kemp | Henry Cromwell |
| Stacy Dorning | Mary Cromwell |
| Melinda Churcher | Bridget Cromwell |
| George Merritt | Old Man William |
| Gerald Rowland | Drummer Boy |
| Josephine Gillick | Elizabeth Cromwell |
| John Welsh | Bishop Juxon |
| Patrick O'Connell | John Lilburne |
| Bryan Pringle | Trooper Hawkins |
Technical Credits
| Ken Hughes | Director,Screenwriter |
| Irving Allen | Producer |
| Frank Cordell | Score Composer |
| Gerry Crampton | Stunts |
| Andrew Donally | Associate Producer |
| Ronald Harwood | Screenwriter |
| Bill Lenny | Editor |
| Vittorio Nino Novarese | Costumes/Costume Designer |
| John Stoll | Production Designer |
| Ted Sturgis | Asst. Director |
| Arthur Taksen | Set Decoration/Design |
| Geoffrey Unsworth | Cinematographer |
| Bill Warrington | Special Effects |
| Herbert Westbrook | Art Director |
