Winston Churchill

Gary Oldman

Acting

Viscount Halifax

Stephen Dillane

Acting

Elizabeth Layton

Lily James

Acting

Neville Chamberlain

Ronald Pickup

Acting

King George VI

Ben Mendelsohn

Acting

Clemmie

Kristin Scott Thomas

Acting

Sir John Simon

Nicholas Jones

Acting

Sir Anthony Eden

Samuel West

Acting

Clement Atlee

David Schofield

Acting

General Ismay

Richard Lumsden

Acting

General Ironside

Malcolm Storry

Acting

Arthur Greenwood

Hilton McRae

Acting

Sir Samuel Hoare

Benjamin Whitrow

Acting

John Evans

Joe Armstrong

Acting

Air Chief Marshal Dowding

Adrian Rawlins

Acting

Admiral Ramsay

David Bamber

Acting

Admiral Dudley Pound

Paul Leonard

Acting

President Roosevelt (voice)

David Strathairn

Acting

Tom Leonard

Eric MacLennan

Acting

Sawyers

Philip Martin Brown

Acting

Cabinet Secretary Bridges

Demetri Goritsas

Acting

Randolph Churchill

Jordan Waller

Acting

Diana Churchill

Alex Clatworthy

Acting

Mary Churchill

Mary Antony

Acting

Sarah Churchill

Bethany Muir

Acting

Pamela Churchill

Anna Burnett

Acting

Lord Stanhope

Jeremy Child

Acting

Lord Kingsley Wood

Brian Pettifer

Acting

Lord Londonderry

Michael Gould

Acting

House of Commons Speaker

Paul Ridley

Acting

Ernle Hastings

Robin Pearce

Acting

Equerry

Michael Bott

Acting

Reynaud

Olivier Broche

Acting

Daladier

Mario Hacquard

Acting

BBC Producer

Pip Torrens

Acting

Actor

Edmund Wiseman

Acting

Abigail Walker

Hannah Steele

Acting

Alice Simpson

Nia Gwynne

Acting

Marcus Peters

Ade Dee Haastrup

Acting

Maurice Baker

James Eeles

Acting

Jessie Sutton

Flora Nicholson

Acting

Young Girl on Tube

Bronte Carmichael

Acting

Agnes Dillon

Roisin O'Neill

Acting

Oliver Wilson

John Locke

Acting

Margaret Jerome

Jo Neary

Acting

Brigadier Nicholson

Richard Glover

Acting

Ramsay Staffer

Tom Ashley

Acting

Reporter

Joshua Higgott

Acting

Teenage Girl at Tube Map

Imogen King

Acting

Naval Map-Room Officer

Miles Gallant

Acting

Sybil

Faye Marsay

Acting

Sir Alexander Cadogan

John Atterbury

Acting

AD Nicholl (Secretary #1)

James Harkness

Acting

W D Wilkinson (Secretary #2)

Joshua James

Acting

Christopher Wilson (Photographer)

Charley Palmer Rothwell

Acting

Maid

Patsy Ferran

Acting

Cook

Sarah Flind

Acting

Back Bencher

Steffan Donnelly

Acting

Cecil Beaton

Kieran Buckeridge

Acting

Member of Parliament (uncredited)

Johnny Otto

Acting

Sentry (uncredited)

Nick Howden-Steenstra

Acting