Bjornsson

Björnsson, often anglicized as Bjornsson, is an Icelandic patronymic surname meaning "son of Björn." In Icelandic naming practice, such patronymics reflect the father's given name rather than a fixed family lineage, so Björnsson indicates that the bearer's father was named Björn. The feminine form is Björnsdóttir, meaning "daughter of Björn." Outside Iceland, Björnsson may be treated as a family surname in legal or social contexts, but its origin remains patronymic for most Icelandic bearers.

Notable bearer: Hafþór Júlíus Björnsson (born 1988), Icelandic strongman and actor, widely known for portraying The Mountain in the television series Game of Thrones. He won the 2018 World's Strongest Man competition and has been recognized for his achievements in strength sports.

Because Björnsson is patronymic rather than a fixed surname in Iceland, there are many individuals who bear the name without being part of a single, traditional family lineage. The name reflects Iceland's distinctive naming conventions, where the listing of a given name and patronymic rather than a inherited surname is common.