Peltigera granulosa is a species of terricolous (ground-dwelling), foliose lichen in the family Peltigeraceae. Found in Papua New Guinea, it was formally described as a new species in 2009 by Emmanuël Sérusiaux, Bernard Goffinet, Jolanta Miądlikowska, and Orvo Vitikainen. The type specimen was collected from open grassland between Gumum and Sape villages, where it was found growing on sand. The species epithet granulosa refers to its characteristic granulose margin.