Young Blades follows D'Artagnan (Hugh Dancy), a young arrogant swordsman; Radegonde (Sarah-Jane Potts), a clever girl he meets in the woods; and a trio of Musketeers as they attempt to thwart a plot to send France and Spain into war.
| Actor | Role |
|---|---|
 Hugh DancyD'Artagnan | D'Artagnan |
 Sarah-Jane PottsRadegonde / Anne | Radegonde / Anne |
| SScott HickmanAthos | Athos |
 Anthony StrachanPorthos | Porthos |
 Callum BlueAramis | Aramis |
| BBen McCosketLouis XIII | Louis XIII |
 Ben CrossCardinal Richelieu | Cardinal Richelieu |
 Anne KreisFrançoise | Françoise |
 Ayda FieldDaughter | Daughter |
 Sian WebberMarie de Médicis | Marie de Médicis |
| BBérénice DuboisWife | Wife |