Hațeg Island was a large offshore island in the Tethys Sea which existed during the Late Cretaceous period, probably from the Cenomanian to the Maastrichtian ages. It was situated in an area corresponding to the region around modern-day Hațeg, Hunedoara County, Romania. Maastrichtian fossils of small-sized dinosaurs have been found in the island's rocks. It was formed mainly by tectonic uplift during the early Alpine orogeny, caused by the collision of the African and Eurasian plates towards the end of the Cretaceous. There is no real present-day analog, but overall, the island of Hainan is perhaps closest as regards climate, geology and topography, though still not a particularly good match. The vegetation, for example, was of course entirely distinct from today, as was the fauna.

The Late Cretaceous is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after creta, the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period.