 Millie Bobby BrownEnola Holmes | Enola Holmes |
 Henry CavillSherlock Holmes | Sherlock Holmes |
 Helena Bonham CarterEudoria Holmes | Eudoria Holmes |
 Louis PartridgeTewkesbury | Tewkesbury |
 Himesh PatelDr. Watson | Dr. Watson |
 Sharon Duncan-BrewsterMoriarty | Moriarty |
 Hattie MorahanLady Tewkesbury | Lady Tewkesbury |
 Susan WokomaEdith | Edith |
 Joe AzzopardiMikiel | Mikiel |
 Nicholas AaronSergeant Nicholas Smith | Sergeant Nicholas Smith |
 Michela FarrugiaCrista | Crista |
 David SterneCoachman Eric | Coachman Eric |
 Jason WatkinsBrigadier Sampson | Brigadier Sampson |
| PPaul CawleyGovernor | Governor |
| MMyron EllulSergeant Indri | Sergeant Indri |
 Robbie O'NeillCorporal Malick | Corporal Malick |
 Stephen ChanceSenior Officer | Senior Officer |
| NNichollette Yardley-MooreBaroness Guildford | Baroness Guildford |
 Bern CollaçoOfficer (uncredited) | Officer (uncredited) |
 Maxime DurandMarket Goer (uncredited) | Market Goer (uncredited) |
 Mike ParishChelmsford an English Aristocrat (uncredited) | Chelmsford an English Aristocrat (uncredited) |
 Theodore ZammitSailor (uncredited) | Sailor (uncredited) |
 James WrightFamily Member (uncredited) | Family Member (uncredited) |
