The fossils of Saltasaurus were excavated by José Fernando Bonaparte, Martín Vince and Juan C. Leal between 1975 and 1977 at the Estancia “El Brete”. The find was in 1977 reported in the scientific literature.
Saltasaurus was named and described by Bonaparte and Jaime E. Powell in 1980. The type species is Saltasaurus loricatus. Its generic name is derived from Salta Province, the region of north-west Argentina where the first fossils were recovered. The specific name means “protected by small armoured plates” in Latin.
The holotype, PVL 4017-92, was found in a layer of the Lecho Formation dating from the early Maastrichtian stage of the Upper Cretaceous period, about seventy million years old. It consists of a sacrum connected to two ilia. Under the inventory number PVL 4017 over two hundred additional fossils have been catalogued. These include rear skull elements, teeth, vertebrae of the neck, back, hip and tail, parts of the shoulder girdle and the pelvis, and limb bones — plus various pieces of armour. These bones represent a minimum of five individuals, two adults and three juveniles or subadults.
Currently the only recognised species of Saltasaurus is S. loricatus. A S. robustus and a S. australis have been suggested but these are now considered to belong to a separate genus, Neuquensaurus. Earlier, armour plates from the area had been named as Loricosaurus by Friedrich von Huene who assumed them to be from an armoured ankylosaurian. It has been suggested these plates were in fact from Saltasaurus.