Tarbosaurus was discovered in 1955, in Mongolia and named Tyrannosaurus bataar. However, there were noticeable differences in the skull of Tarbosaurus. The name was changed from Tyrannosaurus to Tarbosaurus in 1956. At the discovery site, a Tarbosaurus skull and vertebrae were discovered, and since then, many Tarbosaurus remains, including a few complete skeletons, have been uncovered. It has been suggested that Tarbosaurus actually was a species of Tyrannosaurus, putting the name Tarbosaurus at risk, as Tyrannosaurus was discovered nearly half a century before Tarbosaurus.
The name Tarbosaurus was derrived from the Greek tarbos, meaning "alarm" or "terror" and sauros, meaning "lizard" or "reptile". The species name bataar is actually a misspelled version of the Mongolian baatar, meaning "heroic". The name Tarbosaurus battar translates to "heroic alarming reptile" or "heroic terror lizard".