Sara Sara is a 5,505-metre-high (18,061 ft) volcano lying between Lake Parinacochas and the Ocoña River in Peru. It is situated in the provinces of Parinacochas and Paucar del Sara Sara. The volcano formed during the Pleistocene during four different stages of volcanic activity, which constructed a volcanic edifice with an oval outline consisting of lava flows and lava domes. The volcano was glaciated during the last glacial maximum; it may still feature glaciers. The last eruption was about 14,000 years ago and future eruptions are possible. The volcano was worshipped by the local population, and an Inca mummy of a 15-year old girl was found on the summit by archaeologists.

Sara Sara lies within the Cordillera Ampato [es] sub-range of the Andes. Administratively, it is located in the Parinacochas and Paucar del Sara Sara provinces of the Ayacucho Region, Peru. The town of Pausa lies 12 kilometres (7.5 mi) away from the volcano, and agriculture occurs in the valleys of the area. A disused road passes over the southern flank of the volcano and reaches an elevation of 4,600 metres (15,100 ft).

The volcano is 5,505 metres (18,061 ft) high and has an oval outline; the summit lies at the southern end of a north-northwest-south-southeast trending summit ridge. It consists of a complex of lava domes and lava flows superposed on older stratovolcanoes and has a total volume of 20–25 cubic kilometres (4.8–6.0 cu mi), with the edifice rising about 1 kilometre (0.62 mi) above the surrounding terrain. The vents are aligned in north-northeast-south-southwest direction and are accompanied by lateral lava domes. These vents were the source of lava flows and block-and-ash flows generated by the collapse of lava domes. Thick ash deposits underlie viscous lava flows that define the "Mollebamba Volcanics" and reach lengths of 15 kilometres (9.3 mi). A pyroclastic cone of recent age is found on the mountain and a recent lava flow descends the eastern flank. The western flank is heavily eroded. West of the volcano is Lake Parinacochas to its east is the Ocoña River.

Glacial cirques, glacial valleys and numerous moraines surround the volcano. Two past glaciations have been described, "Sara Sara II" which descended to about 4,500 metres (14,800 ft) elevation and also encompassed several peaks south of Sara Sara such as the 4,703 metres (15,430 ft) high Cerro Puca Puca, and "Sara Sara I" which has left moraine networks at lower elevations especially on the southwestern flank. The lowest moraines on the western flank occur at 4,000–4,100 metres (13,100–13,500 ft) while these on the eastern flank only reach 4,300 metres (14,100 ft), presumably because of the effects of later volcanism that erased other moraines. Some of these encompass closed depressions. A third set of moraines at higher elevations appears to correspond to the neoglacial. Pleistocene moraines occur mostly on the western side of the volcano and Holocene ones on the eastern. The last glacial maximum at Sara Sara occurred between 24,000 and 17,000 years ago and the equilibrium line altitude descended to 4,500–4,800 metres (14,800–15,700 ft).

Presently, it reaches 5,200 metres (17,100 ft) elevation at Sara Sara. The mountain has been called glaciated, with an ice cap covering approximately 20 square kilometres (7.7 sq mi), and alternatively, it has been stated that it only has a temporary snow cover. Active rock glaciers extend below the snowline on the western and northern flanks, and inactive rock glaciers are found at lower elevations. Water used for irrigation originates at Sara Sara's foot.

The Quaternary volcanoes of Peru are part of the Central Volcanic Zone (CVZ) of the Andes and Sara Sara is the northernmost member. The CVZ features consists of two arcs of volcanoes on both sides of the Western Cordillera and features composite volcanoes, lava domes and lava flows, of which El Misti, Huaynaputina, Sabancaya, Ticsani, Tutupaca, Ubinas and Yucamane have been active in historical times. Ampato, Chachani, Casiri, Coropuna and Sara Sara are dormant volcanoes. The volcanism is triggered by the subduction of the Nazca Plate underneath the South America Plate, which takes place off the western coast of South America. North of Sara Sara, a gap occurs in the volcanic belt, probably because the Nazca Ridge subducts there.

The basement is formed by Precambrian and Paleozoic rocks, which are covered by Mesozoic and Cenozoic sediments and volcanites. The volcano is part of a 30 kilometres (19 mi) long, fault-controlled chain of volcanoes, which includes Cerro Grande, Yarihuato, Puca Ccasa, Sara Sara, Puca Puca and Cerro Queñuapunco. A major geological lineament known as the Sara Sara lineament runs across the volcano in northwest-southeast direction. Several faults cross the edifice in the same direction, and some were active during the Holocene.

A depression west of Sara Sara which contains the Laguna Parinacochas may be the source of the regional Caraveli ignimbrite that was emplaced 8-9 million years ago. This depression constitutes the 25 by 35 kilometres (16 mi × 22 mi) wide Incahuasi caldera, which may be connected to the magmatic system of Sara Sara.