Gastrotheca ossilaginis is a species of frog in the family Hemiphractidae. It is endemic to Peru. Its natural habitats are subtropical or tropical moist montane forests and pastureland.
The genus name Gastrotheca comes from the Greek words gaster, meaning "stomach," and theke, meaning "box" or "receptacle," as a reference to the distinctive dorsal brood pouch possessed by female Gastrotheca ossilaginis, which protects developing embryos.
Ossilaginis is a Latin adjective meaning "bony hardness"; the name refers to the bony nature of the integumentary-cranial co-ossification in the skull of this species. This is a key characteristic of this species, distinguishing it from other gastrotheca in the region.
Gastrotheca ossilaginis is endemic to northern Peru, confined to the San MartÃÂn region in the Andes. The species occurs exclusively within this region, with no confirmed records outside of Peru.