Styrbiorn m. Old Norse styrr 'tumult, uproar' + Old Norse bjǫrn 'bear'.
One Styrbiorn appears in 10th C Swedish legend as the name of a prince and hero; Lind argues that his name is in fact Biorn (cf. Bjorn) with a prepended byname styrr. However, the prototheme appears in other compounds, making it more likely that Styrbiorn is an ordinary dithematic Scandinavian name.