Pristimantis bearsei is a species of frog in the family Strabomantidae. It is endemic to Peru and only known from the region of its type locality northeast of Tarapoto in the San Martín Region. Common name Bearse's robber frog has been coined for this species.
The specific name bearsei honours Robert Carleton Bearse, an American physicist. As the Associate Vice Chancellor of the University of Kansas, his administration enhanced the programs of the University of Kansas Natural History Museum.
Pristimantis bearsei males measure 23mm26mm and females about 38mm39mm in snout–vent length. The dorsum is shagreen and brown with darker brown marks on back and transverse bars on limbs. The venter is brown with cream flecks. The tympanum is prominent. The toes have lateral fringes but no webbing. Males have vocal slits.
Pristimantis bearsei occur in lower humid montane forest at elevations of 500m–730mm (1,600feet–2,400feetm) above sea level close to streams. Adults have been found on mossy boulders, and some juveniles also on herbaceous vegetation. The species is threatened by habitat loss. Its range overlaps with the Cordillera Azul National Park.