Mark Strong

Stewart Menzies

Charles Dance

Commander Denniston

Matthew Goode

Hugh Alexander

Alex Lawther

Young Alan Turing

David Charkham

Joan's Father

Benedict Cumberbatch

Alan Turing

Victoria Wicks

Joan's Mother

Morten Tyldum

Director

Steven Waddington

Superintendent Smith

Andrew Havill

Teacher

Keira Knightley

Joan Clarke

Tom Goodman-Hill

Sergeant Staehl

Tuppence Middleton

Helen

Matthew Beard

Peter Hilton

Rory Kinnear

Detective Robert Nock

James Northcote

Jack Good

Jack Bannon

Christopher Morcom

Allen Leech

John Cairncross

Ilan Goodman

Keith Furman

Jack Tarlton

Charles Richards

Dominic Charman

Sherborne Student 1

James G. Nunn

Sherborne Student 2

Charlie Manton

Sherborne Student 3

Laurence Kennedy

Headmaster

Tim van Eyken

MI6 Agent

Graham Moore

Executive Producer