Family name Fjölnir (Fjölnir 
) , all over the world, is an extremely rare last name. Much more prevalently, Fjölnir is the forename as well as the last name.
Þrastarson, Sæmundsson, Georgsson, Jónsson, Unnarsson, Baldursson, Gíslason, Ólafsson, Guðmundsson, Þorgeirsson, and Björgvinsson