| Fionn Whitehead | .... | Tommy |
| Damien Bonnard | .... | French Soldier |
| Aneurin Barnard | .... | Gibson |
| Lee Armstrong | .... | Grenadier |
| James Bloor | .... | Irate Soldier |
| Barry Keoghan | .... | George |
| Mark Rylance | .... | Mr. Dawson |
| Tom Glynn-Carney | .... | Peter |
| Tom Hardy | .... | Farrier |
| Jack Lowden | .... | Collins |
| Luke Thompson | .... | Warrant Officer |
| Michel Biel | .... | French Soldier 2 |
| Constantin Balsan | .... | French Soldier 3 |
| Billy Howle | .... | Petty Officer |
| Mikey Collins | .... | Soldier |
| Callum Blake | .... | Stretcher Bearer |
| Dean Ridge | .... | Soldier at The Gap |
| Bobby Lockwood | .... | Able Seaman |
| Will Attenborough | .... | Second Lieutenant |
| Kenneth Branagh | .... | Commander Bolton |
| Tom Nolan | .... | Lieutenant |
| James D'Arcy | .... | Colonel Winnant |
| Matthew Marsh | .... | Rear Admiral |
| Cillian Murphy | .... | Shivering Soldier |
| Adam Long | .... | Sub-Lieutenant |
| Harry Styles | .... | Alex |
| Miranda Nolan | .... | Nurse |
| Bradley Hall | .... | Sailor |
| Jack Cutmore-Scott | .... | Lifeboat Soldier 1 |
| Brett Lorenzini | .... | Lifeboat Soldier 2 |
| Michael Fox | .... | Engineer |
| Brian Vernel | .... | Highlander 1 |
| Elliott Tittensor | .... | Highlander 2 |
| Kevin Guthrie | .... | Highlander 3 |
| Harry Richardson | .... | Private |
| Jochum ten Haaf | .... | Dutch Seaman |
| Johnny Gibbon | .... | Junior Naval Officer |
| Richard Sanderson | .... | Heinkel Spotter |
| Kim Hartman | .... | Stewardess |
| Calam Lynch | .... | Deal Sailor |
| Charley Palmer Rothwell | .... | Corporal |
| Tom Gill | .... | Furious Soldier |
| John Nolan | .... | Blind Man |
| Bill Milner | .... | Lone Private |
| Jack Riddiford | .... | Soldier on RN Launch |
| Harry Collett | .... | Boy |
| Eric Richard | .... | Man at Railway Window |
| Sam Aronow | .... | British Expeditionary Force Soldier (uncredited) |
| Simon Ates | .... | British Expeditionary Force Soldier (uncredited) |
| Caleb Bailey | .... | Soldier (uncredited) |
| Aldo Beqiri | .... | French Soldier (uncredited) |
| Michael Caine | .... | Fortis Leader (uncredited, voice) |
| Dennis Eleveld | .... | Schoolboy / Soldier (uncredited) |
| Paul Riley Fox | .... | British Soldier (uncredited) |
| Jack Gover | .... | British Soldier (uncredited) |
| Sander Huisman | .... | British Expeditionary Force Soldier (uncredited) |
| Samgar Jacobs | .... | Royal Navy (uncredited) |
| Christian Janner | .... | British Soldier (uncredited) |
| Jedediah Jenk | .... | British Expeditionary Force Soldier (uncredited) |
| Davey Jones | .... | British Soldier / Station Officer (uncredited) |
| Han Leopold | .... | Marine (uncredited) |
| Samuel Louwagie | .... | Soldier (uncredited) |
| Valiant Michael | .... | Warrant Officer (uncredited) |
| Thomas Millet | .... | French Soldier (uncredited) |
| Johnny Otto | .... | Captain Marshall (uncredited) |
| Crystal Pereyra | .... | Nurse on Destroyer (uncredited) |
| Robby Prinsen | .... | Royal Navy Officer (uncredited) |
| Christian Roberts | .... | Royal Navy Officer (uncredited) |
| Jan-Michael Rosner | .... | British Soldier (uncredited) |
| Connor Ryan | .... | British Soldier (uncredited) |
| Pierre Valle | .... | Soldier (uncredited) |
| Michiel van Ieperen | .... | Royal Navy Sailor (uncredited) |
| Bram Vlot | .... | Royal Navy Sailor (uncredited) |
| Olav Vollebregt | .... | Royal Navy Sailor (uncredited) |
| Nick Vorsselman | .... | British Expeditionary Force Soldier (uncredited) |
| Merlijn Willemsen | .... | British Soldier on the Sittard (uncredited) |
| Nirman Wolf | .... | Marine (uncredited) |