Nathan O'Toole as Bjorn Ironside, Ragnar and Lagertha's son.David Pearse as Svein, the loyal henchman of Earl Haraldson.John Kavanagh as The Seer, the seiðmann of Kattegat.Alyssa Sutherland as Princess Aslaug, a love interest of Ragnar, claiming to be the daughter of the valkyrie Brynhildr.George Blagden as Athelstan, an Anglo-Saxon monk captured by Ragnar on his first raid in England.Gabriel Byrne as Earl Haraldson, Earl of the settlement known as Kattegat, the home of Ragnar.Gustaf Skarsgård as Floki, a gifted shipbuilder and Ragnar's friend.
Jessalyn Gilsig as Siggy, Earl Haraldson's wife.Clive Standen as Rollo, Ragnar's brother.Katheryn Winnick as Lagertha, Ragnar's wife, and a shield-maiden.Travis Fimmel as Ragnar Lothbrok, a Viking farmer and warrior who yearns to raid the rumoured riches of undiscovered England.See also: List of Vikings characters Main
