E. Rossoni notes that this surname derives from the medieval name of Frankish origin Gabaldus, documented in Arles, in Provence, among the Templars who set out towards the Crusades in 1175, where a certain Bertrandus Gabaldus figures. That name comes from the Germanic Wadbald, composed of wad ("commitment") and bald ("bold"), meaning "determined in boldness". Rossoni also contemplates a derivation from the medieval French name Gabaud or from the Germanic Wadivald, formed by wadi ("commitment") and waldan ("to govern"), with the sense of "the one who governs with dedication".

An additional hypothesis proposed by Rossoni points to ethnic forms originated in the name of the Gaulish people of the Gabali, settled in the Languedoc. According to the scholar Olivieri, cited by Rossoni, Gabaldo would derive from the Germanic personal name Gabuard, documented in Förstemann.

F. De Laurentiis proposes, on the other hand, a different etymology: the surname would have arisen as a trade name applied to the boatmen who operated flat-bottomed cargo barges, known as gabare.

The documented variants include Gabaldi, with presence in the Turin area, the north of the Milan area, the Varese area and the Rovigo area; Gabaldo, located between the Verona and Padua areas, and in the Bologna area; Gavaldo, peculiar to the Savona and Imperia areas; and Gavaudo, practically unique.