The Pannonian Steppe is a variety of grassland ecosystems found in the Pannonian Basin. It is an exclave of the Great Eurasian Steppe, found in modern-day Austria, Bulgaria, Hungary, Romania, Serbia, Slovakia and easternmost parts of Croatia.

The Pannonian Basin, or Carpathian Basin, is a large sedimentary basin situated in southeast Central Europe. After the WW1 and Treaty of Trianon, the geomorphological term Pannonian Plain became more widely used for roughly the same region though with a somewhat different sense, with only the lowlands, the plain that remained when the Pliocene Epoch Pannonian Sea dried out.