 | Charlie Hunnam als Arthur |
 | Astrid Bergès-Frisbey als The Mage |
 | Jude Law als Vortigern |
 | Djimon Hounsou als Bedivere |
 | Eric Bana als Uther |
 | Aidan Gillen als Bill |
 | Freddie Fox als Rubio |
 | Craig McGinlay als Percival |
 | Mikael Persbrandt als Greybeard |
 | Tom Wu als George |
 | Kingsley Ben-Adir als Wet Stick |
 | Neil Maskell als Back Lack |
 | Annabelle Wallis als Maggie |
 | Peter Ferdinando als Earl of Mercia |
 | Geoff Bell als Mischief John |
 | Katie McGrath als Elsa |
 | Lorraine Bruce als Syren 1 |
 | Eline Powell als Syren 2 |
 | Hermione Corfield als Syren 3 |
 | Zac Barker als Young Arthur 2 Yrs |
| Oliver Barker als Young Arthur 2 Yrs |
 | Poppy Delevingne als Igraine |
 | Millie Brady als Catia |
| Nicola Wren als Lucy |
 | Wil Coban als Brother Blackleg |
| Bleu Landau als Blue |
 | Jacqui Ainsley als Lady of the Lake |
 | Georgina Campbell als Kay |
| Rob Knighton als Mordred |
| Michael Hadley als Mage King |
 | David Beckham als Trigger |
 | Alan Turkington als General 1 |
 | Michael McElhatton als Jack's Eye |
 | Charlie Rawes als Axeman |
 | James Warren als Mike |
| Ellie Graham als Maria |
 | Kamil Lemieszewski als Merlin |
 | Kalle Hennie als Viking |
 | Peter Guinness als Baron 1 |
 | Mark Umbers als Baron 2 |
 | Adrian Bouchet als Baron 3 |
 | Florence Bell als Woman 1 |
| Anna Brooks Beckman als Woman 2 |
 | Cordelia Bugeja als Woman 3 |
 | Rebecca Calder als Maid 1 |
 | Lee Nicholas Harris als Dan Clan Mafia (uncredited) |
 | Gintare Beinoraviciute als Noble (uncredited) |
| Alice E. Mayer als Noble Girl (uncredited) |
 | Claira Watson Parr als Noblewoman (uncredited) |
 | Alphonso Austin als Slave Labourer (uncredited) |
 | Rudy Barrow als Londinium Fighter (uncredited) |
 | Daniel Stisen als SPAC / Londinum Fighter (uncredited) |
 | Joel Bryant als Londinium Fighter (uncredited) |
 | Dacio Caballero als Fighter (uncredited) |
 | Lucy Chappell als Young Mother (uncredited) |
 | Jamie B. Chambers als Knight (uncredited) |
| Pedro Caxade als Vortigern's Guard (uncredited) |
 | Nick Cornwall als Clan Head 1 (uncredited) |
 | Steve Barnett als Brothel Punter (uncredited) |
 | Guy Ritchie als Inn Owner |
 | Steen Young als Nemesis (uncredited) |
 | Jason Lines als Miscellaneous (uncredited) |
| John Mathieson | Director of Photography |
| Guy Ritchie | Screenplay |
| Guy Ritchie | Director |
| Guy Ritchie | Producer |
| Bruce Berman | Executive Producer |
| Akiva Goldsman | Producer |
| Brian Donovan | Unit Production Manager |
| Gemma Jackson | Production Design |
| James Boyle | Sound Designer |
| Peter Burgis | Foley |
| Lionel Wigram | Screenplay |
| Lionel Wigram | Producer |
| Tina Jones | Set Decoration |
| Alex Bicknell | Visual Effects Producer |
| Annie Symons | Costume Design |
| Denis Schnegg | Supervising Art Director |
| David Dobkin | Executive Producer |
| David Dobkin | Story |
| James Herbert | Editor |
| James Herbert | Executive Producer |
| Philip Hedgecock | First Assistant Editor |
| Steve Clark-Hall | Producer |
| Joby Harold | Screenplay |
| Joby Harold | Producer |
| Joby Harold | Story |
| Paul Edwards | Steadicam Operator |
| Andrew Stirk | Sound Re-Recording Mixer |
| Paul Hayes | Third Assistant Director |
| Elizabeth West | Script Supervisor |
| Michael Schlingmann | Storyboard Artist |
| Nick Davis | VFX Supervisor |
| Luigi Marchione | Art Direction |
| Daniel Pemberton | Original Music Composer |
| Tory Tunnell | Producer |
| Reg Poerscout-Edgerton | Casting |
| Sue Harding | Foley |
| Jennifer Fairweather | Visual Effects Producer |
| Philipp Wolf | Visual Effects Producer |
| Luke Hull | Art Direction |
| Tabitha Quitman | Art Department Coordinator |
| Stevee Davies | Casting Assistant |
| Paul Driver | Visual Effects Producer |
| Thomas Brown | Art Direction |
| Jonathan Fawkner | Visual Effects Supervisor |
| Luan Placks | Assistant Costume Designer |
| Marco Scotti | Costume Supervisor |
| Dominic Gibbs | Supervising Sound Editor |
| Jason Swanscott | Foley |
| Sean Barclay | Location Scout |
| Simon Changer | Music Editor |
| Ben Meechan | Sound Effects Editor |
| Chuck Finch | Gaffer |
| Jinnie Pak | Visual Effects Producer |
| Anthony Caron-Delion | Art Direction |
| John Gamble | Camera Operator |
| Chris Burdon | Sound Re-Recording Mixer |
| Katrina Mackay | Assistant Art Director |
| Marianne Huet | Script Supervisor |
| Katherine Tibbetts | Production Manager |
| Donald McInnes | Makeup Artist |
| Chris Plevin | Camera Operator |
| Mike Valentine | Underwater Camera |
| John Marzano | Aerial Director of Photography |
| Martin Chamney | Pre-Visualization Supervisor |
| Danny Sheehan | ADR Supervisor |
| Midge Ferguson | Location Manager |
| Derek Burgess | VFX Editor |
| Nuria Mbomio | Makeup Artist |
| James Collins | Art Direction |
| Christine Blundell | Hair Designer |
| Christine Blundell | Makeup Designer |
| Hayley Easton Street | Art Direction |
| Alan Stewart | Second Unit Director of Photography |
| Matthew Skelding | Dialogue Editor |
| Steven Mnuchin | Executive Producer |
| Wick Finch | Gaffer |
| Flora Moody | Makeup Artist |
| Paul Dennis | Set Dresser |
| Linda O'Reilly | Set Costumer |
| Max Keene | Associate Producer |
| Max Keene | First Assistant Director |
| Karen Elliott | Music Supervisor |
| Lisa Shanley | Assistant Costume Designer |
| Oliver Cubbage | CG Supervisor |
| Andrew Palmer | Art Direction |
| Lillie Jeffrey | Casting Associate |
| Daniel Smith | Still Photographer |
| Adam Horley | Dialogue Editor |
| Louis Paré | CG Supervisor |
| Greg Corke | Armorer |
| Michael Cliett | Digital Effects Supervisor |
| Matthew Clarke | Location Manager |
| Bernd Angerer | Animation Director |
| Sheara Abrahams | Assistant Costume Designer |
| Oliver Carroll | Art Direction |
| Malwina Suwinska | Makeup Artist |
| Marc Wolff | Aerial Coordinator |
| Marc Wolff | Pilot |
| Eric Petey | Animation Supervisor |
| Ciarán Keenan | Visual Effects Producer |
| Uli Meyer | Storyboard Artist |
| Zoe Freed | Foley |
| Terry Archer | Set Costumer |
| Claire Matthews | Makeup Artist |
| Matt Adams | Digital Intermediate |
| Kevin Daly | Production Manager |
| Lucia Foster Found | Aerial Coordinator |
| Darrell Warner | Costume Illustrator |
| Toby Plaskitt | Russian Arm Operator |
| Katy Covell | Casting Assistant |
| Ollie Gilbert | Casting Assistant |
| Marta Padilla | 3D Modeller |
| Zach Marshall | Assistant Editor |
| Kevin Penney | Foley Editor |
| Angus Munro | Second Film Editor |
| Alastair Don | Location Scout |
| Ben Smithers | Assistant Sound Editor |
| Daniel Hillary | Third Assistant Director |
| Shawn White | Gaffer |
| Gary Nolan | Rigging Gaffer |
| Steve Ellingworth | Key Grip |
| Paul Worley | Key Grip |
| Guy Bennett | Key Grip |
| Brad Silby | Animation Supervisor |
| Courtney McClain | Assistant Costume Designer |
| Tessa Phillips | Assistant Costume Designer |
| Celia Yau | Assistant Costume Designer |
| Sophie Bugeaud | Assistant Costume Designer |
| Amy Lyons | Costume Coordinator |
| Philippa Wood | Costume Coordinator |
| Loulou Bontemps | Set Costumer |
| Tim Perkins | Tailor |
| Michael Crusz | Digital Intermediate |
| Evelien Kortum | Script Supervisor |
| Will Samuelson | Aerial Coordinator |
| William Sumpter | Armorer |
| Omar Morsy | Animation Supervisor |
| Leah Beevers | CG Supervisor |
| Jonathan Vaughn | CG Supervisor |
| Stuart Penn | CG Supervisor |
| Janek Lender | Pre-Visualization Supervisor |
| Brian Pohl | Pre-Visualization Supervisor |
| Steph Lynn Robinson | Stereoscopic Coordinator |
| Leah Jones | VFX Editor |
| Fiona Foster | Visual Effects Producer |
| Daniel Rogers | Health and Safety |
| Georgia Warner | Art Direction |
| Michael Eaton | Graphic Designer |
| Ana McKillop | Special Effects Technician |
