The surname Bersezio is of clearly toponymic origin and is linked to Piedmontese territory. According to E. De Felice, it is formed from the place name Bersézio (province of Cuneo), following a pattern frequent in Italian onomastics, where the place of provenance becomes an identifying element of the lineage.

Along the same lines, E. Rossoni confirms this geographical origin, specifying that the surname is typical of the Cuneo area and derives specifically from Bersezio di Argentera, an Alpine locality of that province. This agreement between authors reinforces the interpretation of a surname arisen to indicate the territorial origin of its bearers.

Taken together, both perspectives agree in pointing to a strictly toponymic origin, linked to a specific locality of Piedmont, with no evidence of alternative occupational or anthroponymic derivations.