Magyarosaurus is a genus of dwarf sauropod dinosaur from late Cretaceous Period in Romania. It is one of the smallest-known adult sauropods, measuring only 6 m (20 ft) in length and 750–1,000 kg (1,650–2,200 lb) in body mass. The type and only certain species is Magyarosaurus dacus. It has been found to be a close relative of Rapetosaurus in the family Saltasauridae in the sauropod clade Titanosauria in a 2005 study.

The Sânpetru Formation is an early Maastrichtian geologic formation. Dinosaur remains are among the fossils that have been recovered from the formation. It is located in Romania, near Sânpetru village, part of Sântămăria-Orlea commune. It forms a component of the Hațeg Island fauna.