Erliansaurus is a genus of therizinosaur theropod dinosaur that lived in Asia during the Cenomanian stage of the Late Cretaceous period in what is now Nei Mongol, Iren Dabasu Formation.

Therizinosaurs are an extinct group of large herbivorous theropod dinosaurs whose fossils have been found across the Middle Jurassic to Late Cretaceous deposits in Europe, Asia and North America. Various features of the forelimbs, skull and pelvis unite these finds as both theropods and maniraptorans, making them relatives of birds. The name of the representative genus, Therizinosaurus, is derived from the Greek θερίζω and σαῦρος. The older representative, Segnosaurus, is derived from the Latin sēgnis ('slow') and the Greek σαῦρος.