E. Rossoni notes that the surname derives from the medieval name Gibertus or Giubertus, in turn from the Frankish name Gerbert or from its medieval French derivatives Gilbert or Girbers, documented in the Baldus of Teofilo Folengo. In a later addition, Rossoni specifies that the forms Gibertus and Wibertus appear in documents from the Modena area from 1032 and 1069 respectively, and traces its root back to the Germanic personal name Wigberht, compounded from wîg ("battle") and berht ("illustrious, famous"), with the sense of "illustrious in battle".

V. Blunda studies it as a Sicilian surname and proposes a different Germanic etymology: the compound Gil Berht, formed by gil ("hostage, legal pledge handed over as a guarantee of a pact") and berht ("bright, illustrious"), with the meaning "illustrious through the hostage" or "famous guarantor". Blunda notes that in early medieval diplomacy the handing over of a hostage guaranteed treaties, truces or alliances, which gave the name a precise legal and political connotation. He adds that the variant Giliberto preserves the linking vowel characteristic of some Romance adaptations of the Germanic compound.

As for geographical distribution, Rossoni places the surname in the region of Emilia-Romagna, with a probable origin in the Modena area, while the variant Giuberti would be proper to Parma and its province. Blunda, by contrast, records it in Sicily.