Oreobates ayacucho is a species of frogs in the family Strabomantidae. It is endemic to Peru and known from a few localities in the Ayacucho Region in the Peruvian Andes. The species is only known from 11 specimens.
The female holotype measures 29mm in snout–vent length (SVL). Two adult males measure 19mm25mm SVL. The snout is short and rounded. The tympanic membrane is absent but the tympanic annulus is visible beneath skin, partly covered by supratympanic. Skin on the dorsum is smooth and has small, elongate tubercles, and forms discontinuous occipital and dorsolateral folds. Fingers and toes have knob-shaped terminal phalanges but no webbing. The dorsum and venter are dark brown, with the folds and some warts almost black. The iris is almost black and has some golden reticulation.
The male advertisement call consists of a group of 3–5 pulsed, amplitude-modulated notes. The call lasts less than a second, but is repeated at a rate of 2.5–2.9 calls per minute when males are motivated.
Individuals have been found in cold puna grassland at elevations of 3411m–3850mm (11,191feet–12,630feetm) above sea level. Males have been heard calling by day. Individuals can hide under thick layers of moss near the ground or within piles of stones. The habitat of this species is threatened by overgrazing from cattle and construction of gas projects. Also burning and collection of the grass could be threats.