| Travis Fimmel | Ragnar Lothbrok |
| Katheryn Winnick | Lagertha |
| Clive Standen | Rollo |
| Jessalyn Gilsig | Siggy Haraldson |
| Gustaf Skarsgård | Floki |
| George Blagden | Athelstan |
| Alexander Ludwig | Bjorn Lothbrok |
| Alyssa Sutherland | Princess Aslaug |
| Donal Logue | King Horik |
| Linus Roache | King Ecbert |
| Amy Bailey | Princess Kwenthrith |
| Ivan Kaye | King Aelle |
| Gaia Weiss | Porunn |
| Jefferson Hall | Torstein |
| Edvin Endre | Erlendur |
| Moe Dunford | Aethelwulf |
| Philip O'Sullivan | Bishop Edmund |
| Sarah Greene | Judith |
| Cathal O'Hallin | Hvitserk
(as Cathál O'Hallin) |
| Cormac Melia | Ubbe |
| Carrie Crowley | Elisef |
| Gary Kenneally | Bjarke |
| Robert MacDomhnail | Viking Warrior
(uncredited) |
| Celine Nihicidhe | Shield Maiden
(uncredited) |