Pyrgophorus spinosus, common name the spiny crownsnail, is a species of very small freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Hydrobiidae.

Pyrgophorus spinosus was described by Richard Ellsworth Call and by Henry Augustus Pilsbry in 1886 as Pyrgulopsis spinosus[1] but until César Marie Félix Ancey established the new genus Pyrgophorus in 1888, it was not clear what genus this species belonged to.

The epidermis is light horn in color, nearly white at apex, with microscopic longitudinal revolving striae and shining.

The peristome is sharp, simple, slightly reflected near the columella, suggesting a faint umbilicus.

[1] The type locality is Comal Creek, a clear stream at New Braunfels, Texas, on rocky bottoms.