The genus was first described by Albert-Félix de Lapparent and Georges Zbyszewski in 1957.[1] The type species is Lusitanosaurus liasicus. The generic name is derived from Lusitania, the ancient Latin name for the region. The specific name refers to the Lias. Originally assigned to the Stegosauria by de Lapparent, Lusitanosaurus is today considered a basal member of the Thyreophora, perhaps belonging to the Scelidosauridae. Some authors consider it a nomen dubium.