| Katheryn Winnick | Lagertha |
| Gustaf Skarsgård | Floki |
| Alexander Ludwig | Bjorn Lothbrok |
| John Kavanagh | Seer |
| Peter Franzén | King Harald Finehair |
| Jasper Pääkkönen | Halfdan the Black |
| Alex Høgh Andersen | Ivar
(as Alex Høgh) |
| Marco Ilsø | Hvitserk |
| Jordan Patrick Smith | Ubbe |
| Jonathan Rhys Meyers | Bishop Heahmund |
| Clive Standen | Rollo |
| Josefin Asplund | Astrid |
| Adam Copeland | Kjetill Flatnose |
| Kris Holden-Ried | Eyvind |
| Ida Nielsen | Margrethe
(as Ida Marie Nielsen) |
| Georgia Hirst | Torvi |
| Dagny Backer Johnsen | Snaefrid |
| Kieran O'Reilly | White Hair |
| Anthony Brophy | King Svase |
| Ryan Henson | Hali |
| Svea Killoran | Asa |
| Ben Roe | Guthrum |
| Mabel Hurley | Young Lagertha |
| Ross Matthew Anderson | Lagertha's Father |
| James Craze | Bul |
| Leah McNamara | Aud |
| Jack McEvoy | Helgi the Lean |
| Mei Bignall | Thorunn |
| Kelly Campbell | Ingvild |
| Rob Malone | Thorgrim |
| Scott Graham | Frodi |
| Donna Dent | Rafarta |
| Elijah Rowen | Asbjorn |
| Lulubelle Earley | Jorunn |
| Lianne Bowley | Shield Maiden
(uncredited) |
| Aoife Byrne | Shield Maiden
(uncredited) |
| Katie Castle | Shield Maiden
(uncredited) |
| Jordan Coombes | Shield Maiden
(uncredited) |
| Karin Floengard Jonsson | Shield Maiden
(uncredited) |
| John Mulvey | Viking
(uncredited) |
| Laura Sibbick | Shield Maiden
(uncredited) |
| Lauterio Zamparelli | Viking
(uncredited) |