| Travis Fimmel | Ragnar Lothbrok |
| Katheryn Winnick | Lagertha |
| Clive Standen | Rollo |
| Jessalyn Gilsig | Siggy Haraldson |
| Gustaf Skarsgård | Floki |
| Gabriel Byrne | Earl Haraldson |
| John Kavanagh | The Seer |
| David Pearse | Svein |
| Nathan O'Toole | Bjorn |
| Eddie Drew | Odin |
| Ruby O'Leary | Gyda |
| Gerard McCarthy | Brondsted |
| Billy Gibson | Ulf |
| Eddie Elks | Olafur |
| David Wilmot | Olaf Andwend |
| Conor Madden | Eric Trygvasson |
| Donna Dent | Woman |
| Cian Quinn | Olaf, Son of Igolf |
| Daniel Aherne | Viking Warrior
(uncredited) |
| Christopher Dane | Condemned Man
(voice) (uncredited) |
| Stav Dvorkin | Baltic warrior
(uncredited) |
| Thorbjørn Harr | Jarl Borg
(uncredited) |
| Eric Higgins | Knut
(uncredited) |
| Vladimir Kulich | Eric
(uncredited) |
| Robert MacDomhnail | Viking Warrior
(uncredited) |
| Riku Rokkanen | Viking
(voice) (uncredited) |