Speyeria adiaste, the unsilvered fritillary or adiaste fritillary, is a species of butterfly of the family Nymphalidae.

The upper side of the male can range from a pale reddish tan to a bright brick red.

Dark markings are scattered and small expect on the bold post median line.

The underside can range from a pale yellow to a gray.

The hindwing spots are unsilvered and barely contrast with the background color.