The authors agree that the surname derives from a personal name of Germanic Lombard origin compounded from two elements: walha ("foreigner, Celt or Romance-speaker") and berhta ("bright, famous"). V. Blunda specifies that the original compound is Walha Berhta, with the sense "illustrious among foreigners" or "famous foreigner", and notes the Sicilian character of the surname. It is further held that the underlying Germanic form is Walpert, meaning "bright, illustrious foreigner", and that the term walh was used by the Germanic peoples to designate the Romanized Celtic populations during the medieval migrations.

E. Rossoni notes that the surname is very rare and that its area of origin is hard to determine, and links it to the medieval name Gualberto, documented as early as the 10th century in the figure of the nobleman Gualberto, of the marquises of Ivrea. Blunda adds as a historical point of reference Saint John Gualbert (c. 985–1073), the Florentine monk who founded the Vallombrosan order, whose figure helped spread the personal name from which this surname derives.