Illampu, Mountain summit in Cordillera Real, Bolivia.

Illampu is a snow-covered mountain in the Cordillera Real of the Bolivian Andes, in the Sorata municipality of Larecaja province, La Paz department. It rises to 6,485 metres, making it the highest peak of the Cordillera Real and the second highest in Bolivia after Sajama. Together with the neighbouring Ancohuma it forms a single massif of about 200 km², and its snowline lies at 5,200 metres.

Illampu was first climbed on 7 June 1928 via the Southwest Ridge by Hans Pfann, Alfred Horeschowsky and Hugo Hörtnagl of Germany and Erwin Hein of Austria. The massif is built of Paleozoic intrusive rock pushed up by plutonic intrusions in the Mesozoic and Tertiary, then exposed by erosion.

Local Aymara communities near Illampu maintain traditions of offering ceremonies to mountain spirits before expeditions begin their journey toward the peak.

Climbers should plan for at least nine days to complete the full ascent starting from La Paz, with several camps established along the route. Proper acclimatization and gradual altitude adjustment are essential for a safe climb.

Illampu and its neighbour Janq'u Uma form a single massif, and within it lies Laguna Glaciar, the 17th highest lake in the world. The massif covers roughly 200 km², making it one of the largest mountain volumes in the Bolivian Andes.