An affair between the second in line to Britain's throne and the princess of the feuding Irish spells doom for the young lovers.
| Actor | Role |
|---|---|
 James FrancoTristan | Tristan |
 Sophia MylesIsolde | Isolde |
 Rufus SewellMarke | Marke |
 David O'HaraDonnchadh | Donnchadh |
 Mark StrongWictred | Wictred |
 Henry CavillMelot | Melot |
 Bronagh GallagherBragnae | Bragnae |
 Ronan VibertBodkin | Bodkin |
 Lucy RussellEdyth | Edyth |
 JB BlancLeon | Leon |
| GGraham MullinsMorholt | Morholt |
 Leo GregorySimon | Simon |
 Dexter FletcherOrick | Orick |
 Richard DillaneAragon | Aragon |
 Hans Martin StierKurseval | Kurseval |
 Thomas MorrisKaye | Kaye |
 Jamie Thomas KingAnwick | Anwick |
 Wolfgang MüllerRothgar | Rothgar |
 Cheyenne RushingLady Serafine | Lady Serafine |
 Barbora KodetováLady Marke | Lady Marke |
| IIsobel MoynihanYoung Isolde | Young Isolde |
 Thomas Brodie-SangsterYoung Tristan | Young Tristan |
| GGordon TruefittTournament Judge | Tournament Judge |
| MMyles TaylorYoung Melot | Young Melot |
| JJack MontgomeryYoung Simon | Young Simon |
 Marek VašutLuther | Luther |
| DDavid FisherIrish Soldier | Irish Soldier |
| BBronwen DaviesLady Aragon | Lady Aragon |
 Philip O'SullivanPaddreggh | Paddreggh |
| NNevan FineganTournament Crier | Tournament Crier |