Boloria thore, the Thor's fritillary, is a butterfly of the family Nymphalidae.

It occurs in damp places in the Alps, Fennoscandia, the south of European Russia, the Urals and east across the Palearctic to Siberia and Japan.

The nymotypical form of this species is easily recognized by the prevalence of black on the upperside.

This colour predominates to such a degree as in other species is only the case in melanistic aberrations.

In the Alps, but at moderates heights in the forest region, not above 6000 ft. Also in the high North, Scandinavia and Finland.