Pumasillo, Mountain summit in La Convención Province, Peru.

Pumasillo is a peak in the Vilcabamba mountain range in La Convencion Province, rising to approximately 5,991 meters. The mountain features steep slopes and multiple summit points throughout its Andean structure.

The mountain was first climbed on July 26, 1957, when mountaineers Mike Gravina and Simon Clark reached the summit via the west ridge. This successful ascent opened the route to climbers in later years.

Pumasillo means "puma claw" in Quechua, from puma (cougar) and sillu (claw). The same name is applied to the whole massif, which also carries the alternative name Sacsarayoc. The peaks Pumasillo, Sacsarayoc and Lasunayoc form this group within the Vilcabamba range.

Climbers need advanced mountaineering gear and proper acclimatization to the altitude before attempting the ascent. The extreme elevation and technical terrain require experience and thorough preparation.

Pumasillo is the highest summit of a massif that also carries Sacsarayoc and Lasunayoc. Its nearest higher peak is Salcantay, 30.9 km away, and the saddle linking them drops to 4,594 m, giving Pumasillo a prominence of 1,397 m. Digital elevation models give heights between 5,849 and 5,991 m.