E. Rossoni notes that this surname derives, by direct reduction or through simple or compound diminutives, from names of Frankish origin such as Ansgard, Ermengard or Hildegard, or from medieval Germanic names such as Edgard, Liutgard, Madelgard or others similar.

V. Blunda, on the other hand, proposes for the Sicilian sphere a different etymology: the surname would derive from the personal name Gardo, linked to the Germanic root gardi, which designated the space delimited by a fence, both the cultivated orchard and the protected family property. This root is preserved in the German Garten, the English garden and the Spanish jardín (by way of French), and also appears in place names of Norse mythology such as Ásgarðr or Miðgarðr.

As for its geographical distribution, Rossoni identifies different independent clusters of origin in several regions of Italy. The surname in its base form presents nuclei in the Venice area, in the area between Bologna, Ferrara and Ravenna, in the Perugia area and in the Cosenza area. The derived forms show their own distributions: Gardin is characteristic of the Veneto, in the provinces of Padua, Venice and Treviso; Gardini is peculiar to the Bologna, Ravenna and Forlì area; and Gardino is of Piedmontese origin.