- Richard Harris
- Oliver Cromwell
- Alec Guinness
- King Charles 'Stuart' I
- Robert Morley
- The Earl of Manchester
- Dorothy Tutin
- Queen Henrietta Maria
- Frank Finlay
- John Carter
- Timothy Dalton
- Prince Rupert
- Patrick Wymark
- The Earl of Strafford
- Patrick Magee
- Hugh Peters
- Nigel Stock
- Sir Edward Hyde
- Charles Gray
- The Earl of Essex
- Michael Jayston
- Henry Ireton
- Richard Cornish
- Oliver Cromwell II
- Anna Cropper
- Ruth Carter
- Michael Goodliffe
- Solicitor General
- Jack Gwillim
- General Byron
- Basil Henson
- Hacker
- Patrick Holt
- Captain Lundsford
- Stratford Johns
- President Bradshaw
- Geoffrey Keen
- John Pym
- Anthony May
- Richard Cromwell
- Ian McCulloch
- John Hampden
- Patrick O'Connell
- John Lilburne
- John Paul
- General Digby
- Llewellyn Rees
- The Speaker
- Robin Stewart
- Charles - Prince of Wales
- Andre Van Gyseghem
- Archbishop Rinucinni
- Zena Walker
- Mrs. Cromwell
- John Welsh
- Bishop Juxon
- Douglas Wilmer
- Sir Thomas Fairfax
- Anthony Kemp
- Henry Cromwell
- Stacy Dorning
- Mary Cromwell
- Mel Churcher
- Bridget Cromwell
- George Merritt
- William
- Gerald Rowland
- Drummer Boy
- Josephine Gillick
- Elizabeth Cromwell
- Peter Bennett
- (scenes deleted)
- Tony Caunter
- (scenes deleted)
- George A. Cooper
- (scenes deleted)
- Bryan Pringle
- Trooper Hawkins
- Lewis Alexander
- Parliamentarian
- Jack Armstrong
- Parliamentarian
- Roy Beck
- Member of Parliament
- Mary Burleigh
- (unknown)
- Bill Burns
- Guard at Execution
- David Charkham
- Royalist Drummer
- Jimmy Charters
- Parliamentarian
- Harold Coyne
- Parliamentarian
- Billy Dean
- Soldier
- Jack Dearlove
- Man in Crowd
- Alistair Dick
- Puritan
- Hugh Elton
- Judge
- Harry Fielder
- Man in Parliament
- John Forbes-Robertson
- Colonel Harrison
- Derek Glynne-Percy
- Spectator
- Ron Gregory
- Court Recorder
- Victor Harrington
- Assessor at KIngs Trial
- George Holdcroft
- Lord / Judge (uncredited)
- Billy John
- Judge
- Gerry Judge
- Parliamentarian
- Pat Judge
- Parliamentarian
- Edward Kemp
- (uncredited)
- Nigel Kingsley
- Servant
- Roy Lansford
- Parliamentarian
- Fred Machon
- Priest
- Victor Maddern
- Executioner
- Colin McKenzie
- Parliamentarian
- Ian Selby
- Parliamentarian
- Jack Sharp
- Man in Church
- Guy Standeven
- Courtier
- Reg Thomason
- Man at Arms
- Paul Tropea
- Boy Outside Parliament
- Rosetta Tropea
- Girl Outside Parliament
- Robert van Kaphengst
- Independent
- Bert Vivian
- Parliamentarian
- Robert Wisepart
- Soldier
- Fred Wood
- Peasant (in church)
