|Portrayed by Faolán Pelleschi|
|Full name:||Sigurd Ragnarsson|
|Parents:|| Ragnar Lothbrok (father)|
|Siblings:|| Bjorn (half-brother)|
|Relatives:|| Rollo (uncle)|
Sigurd "Snake-in-the-Eye" is the third son of Ragnar and Aslaug. Through Ragnar, Sigurd is descended from the Ynglings (descendents of Frey) and the Volsungr (descendents of Odin through his great-grandson Volsung) through his mother.
Aslaug had prophesized that he would be born with the image of the serpent-dragon Fafnir in his eye, the same one her father Sigurd killed. When he was born so, Aslaug named him "Sigurd Snake-in-the-eye" after her father and because of the mark on her son's eye.
- As of the Season 2 finale, Sigurd and his brothers would be known by the Old Norse title of Budlungr or 'prince'.
- Sigurd Ormr i Auga (Snake-in-the-Eye) would eventually inherit and rule over the island of Sjaelland in Denmark, Viken in southern Norway and the lands of Halland and Scania in southern Sweden. He was also the ancestor of a line of Danish kings such as Harthacanute, Gorm the Old, Sweyn Forkbeard and Canute the Great.
- Sigurd is likely named for both Sigurd Hring (Ragnar Lothbrok's father) and Sigurd the Dragonslayer (Aslaug's father).
|Season two appearances|
|Brother's War||Invasion||Treachery||Eye For an Eye||Answers in Blood|
|Unforgiven||Blood Eagle||Boneless||The Choice||The Lord's Prayer|