- Benedict Cumberbatch
- Alan Turing
- Keira Knightley
- Joan Clarke
- Matthew Goode
- Hugh Alexander
- Rory Kinnear
- Detective Robert Nock
- Allen Leech
- John Cairncross
- Matthew Beard
- Peter Hilton
- Charles Dance
- Commander Denniston
- Mark Strong
- Stewart Menzies
- James Northcote
- Jack Good
- Tom Goodman-Hill
- Sergeant Staehl
- Steven Waddington
- Superintendent Smith
- Ilan Goodman
- Keith Furman
- Jack Tarlton
- Charles Richards
- Alex Lawther
- Young Alan Turing
- Jack Bannon
- Christopher Morcom
- Tuppence Middleton
- Helen
- Dominic Charman
- Sherborne Student 1
- James G. Nunn
- Sherborne Student 2
- Charlie Manton
- Sherborne Student 3
- David Charkham
- Joan's Father
- Victoria Wicks
- Joan's Mother
- Andrew Havill
- Teacher
- Laurence Kennedy
- Headmaster
- Tim van Eyken
- MI6 Agent
- Will Bowden
- Military Policeman
- Miranda Bell
- Margaret
- Tim Steed
- Electrical Assistant
- Peter Agnelli
- Navy Captain
- Lee Asquith-Coe
- MI6 Agent
- Hayley Joanne Bacon
- Woman in Crowd
- Lauren Beacham
- RAF Wren
- Ingrid Benussi
- Dancer
- Nicholas Blatt
- Ministry Man
- Carmen Coupeau Borras
- Detective Robert Nock's Secretary
- Jack Brash
- Evacuee
- Jennifer Brenner
- Parent
- Heather Broderick
- Passerby
- Alex Corbet Burcher
- Dancer
- Grace Calder
- Assistant Wren
- Richard Campbell
- Crossword Man in Pub
- Daniel Chapple
- MI6 Agent
- Winston Churchill
- Self
- Lisa Colquhoun
- Joan Clarke's Friend
- Alexander Cooper
- Bletchley Park Agent
- Chris Cowlin
- Military Police Officer
- Ben Davey
- School Boy
- Kirsty-Marie Day
- WRAF Officer
- Leigh Dent
- Passerby
- Esther Eden
- WW2 Wren
- Sam Exley
- Military Policeman 3
- Brian Patrick Farrell
- MI6 Agent
- Ben Farrow
- Military Police
- Samantha Felman
- Wren
- Iulia Filipovscaia
- Switchboard Operator
- Mike Firth
- Crossword Enthusiast
- Alfie Fitch
- Evacuee
- Hannah Flynn
- Wren
- James Gard
- School Boy
- Dennis Good
- Civilian
- Guna Gultniece
- Passerby
- Adolf Hitler
- Self
- Leigh Holland
- M16 Agent
- Luke Hope
- MI6 Exam Agent
- Vera Horton
- Nunn
- Ashley Hudson
- British soldier
- Michael John-Lewis
- Lieutenant
- Samantha Kelly
- Acrobat Act
- Jeremiah Krage
- Acrobat Act
- Debra Leigh-Taylor
- Evacuee
- Stuart Matthews
- Bletchley Park Operative
- Amber-Rose May
- Joan Clarke's Friend
- Kirk McGee
- Acrobat Act
- Arnold Montey
- M16 Agent
- Gina Morrish
- Evacuee
- Adam Nowell
- Technician
- Joseph Oliveira
- M16 Agent
- Ryan Parker
- Young Guy on the Street
- John Redman
- Young Officer
- Julio Romeo
- Police officer
- Tom Sandell
- Civilian
- Adam Scown
- Crossword Soldier
- Scott Stevenson
- Bletchley
- Harry S. Truman
- Self
- Emilia Ufir
- Secretary
- Mark Underwood
- Crossword Man
- Nicola-Jayne Wells
- First Aid Nurse
- Joshua Wichard
- German Spy Plane Pilot