Robert Donat as William Friese-Greene

Margaret Johnston as Edith Harrison Friese-Greene

Maria Schell as Helena Friese-Greene

Renée Asherson as Miss Tagg

Richard Attenborough as Jack Carter

Robert Beatty as Lord Beaverbrook

Martin Boddey as Sitter in Bath Studio

Edward Chapman as Father in Family Group

John Charlesworth as Graham Friese-Greene

Maurice Colbourne as Bride's Father in wedding group

Roland Culver as 1st Company Promoter

John Howard Davies as Maurice Friese-Greene

Michael Denison as Reporter

Joan Dowling as Maggie

Henry Edwards as Fox Talbot's Butler

Mary Ellis as Nell Collings

Marjorie Fielding as Elderly Viscountess

Robert Flemyng as Doctor

Leo Genn as Maida Vale Doctor

Marius Goring as House Agent

Everley Gregg as Bridegroom's Mother

Joyce Grenfell as Mrs Claire

Robertson Hare as Sitter in Bath Studio

Kathleen Harrison as Mother in Family Group

William Hartnell as Recruiting Sergeant

Joan Hickson as Mrs Stukely

Thora Hird as Doctor's Housekeeper

Stanley Holloway as Broker's Man

Patrick Holt as Sitter in Bath Studio

Michael Hordern as Official Receiver

Jack Hulbert as Holborn Policeman

Sidney James as Army Sergeant

Glynis Johns as May Jones

Mervyn Johns as Goitz

Barry Jones as Doctor

Peter Jones as Industry Man

James Kenney as Kenneth Friese-Greene

Ann Lancaster as Bridesmaid in Wedding Group

Herbert Lomas as Warehouse Manager

John Longden as Speaker in Connaught Rooms

Bessie Love as Bride's Mother in Wedding Group

Miles Malleson as Orchestra Conductor

Garry Marsh as Company Promoter

Muir Mathieson as Sir Arthur Sullivan

A.E. Matthews as Old Gentleman

Bernard Miles as Cousin Alfred

Richard Murdoch as Sitter in Bath Studio

John McCallum as Sitter in Bath Studio

David Oake as Claude Friese-Greene

Laurence Olivier as Police Constable 94-B

Cecil Parker as 1st Platform Man

Frank Pettingell as Bridegroom's Father in Wedding Group

Norman Pierce as Speaker in Connaught Rooms

Eric Portman as Arthur Collings

Dennis Price as Harold

Michael Redgrave as Mr. Lege

Peter Reynolds as Bridegroom in Wedding Group

Margaret Rutherford as Lady Pond

Janette Scott as Ethel Friese-Greene

Ronald Shiner as Fairground Barker

Sheila Sim as Nursemaid

Oda Slobodskaya as Soloist at Bath Concert

John Stuart as 2nd Platform Man at Connaught

Marianne Stone as Bride in Wedding Group

Basil Sydney as William Fox-Talbot

Ernest Thesiger as Earl

Sybil Thorndike as Sitter in Bath Studio

David Tomlinson as Lab Asst

Cecil Trouncer as John Rudge

Michael Trubshawe as Sitter in Bath Studio

Peter Ustinov as Industry Man

Frederick Valk as Maurice Guttenburg

Amy Veness as Grandmother in Wedding Group

Charles Victor as Industry Man

Kay Walsh as Hotel Receptionist

Norman Watson as Doctor in Connaught Rooms

Emlyn Williams as Bank Manager

Harcourt Williams as Tom

Googie Withers as Sitter in Bath Studio

Joan Young as Glove Shop Colleague

John Sharp as Film Society Member (uncredited)