Drusilasaura is an extinct genus of possible lognkosaurian titanosaur sauropod dinosaur which lived during the late Cretaceous (Cenomanian-Turonian stage) of Santa Cruz Province of southern Patagonia, Argentina. Drusilasaura was named by César Navarrete, Gabriel Casal and Rubén Martínez in 2011. The type species is Drusilasaura deseadensis. The generic name honours Drusila Ortiz de Zárate, a young female member of the family, also occasioning the choice of the feminine form ~saura. The specific name refers to the Río Deseado.