| Travis Fimmel | Ragnar Lothbrok |
| Clive Standen | Rollo |
| Jessalyn Gilsig | Siggy Haraldson |
| Gustaf Skarsgård | Floki |
| George Blagden | Athelstan |
| Alyssa Sutherland | Aslaug |
| Donal Logue | King Horik |
| Linus Roache | King Ecbert |
| Thorbjørn Harr | Jarl Borg |
| John Kavanagh | The Seer |
| Anna Åström | Hild
(as Anna Aström) |
| Cormac Melia | Ubbe |
| Maude Hirst | Helga |
| Jefferson Hall | Torstein |
| Cathal O'Hallin | Hvitserk
(as Cathál O'Hallin) |
| Jay Duffy | Ari |
| Edvin Endre | Erlendur |
| Robert Fawsitt | Saxon #1 |
| Conor Marren | Saxon #2 |
| James Browne | Messenger |
| Mark Kelvin Ryan | Viking Youth |
| Jordan Coombes | Shield Maiden
(uncredited) |
| Robert MacDomhnail | Viking Warrior
(uncredited) |
| Eimear O'Grady | Shield Maiden
(uncredited) |
| Dean O'Neill | Viking Warrior
(uncredited) |
| Rachel Walker | Shield Maiden
(uncredited) |