The surname Bolzonaro is very rare and presents an origin linked mainly to northeastern Italy. According to E. Rossoni, it is typical of the area comprising Padua and Rovigo, which indicates a regional development within the Veneto.

As for its etymology, E. Rossoni proposes as the main hypothesis a toponymic derivation from Bolzano Vicentino (Vicenza area), which places it within the group of surnames that identify the place of provenance of the lineage. However, he also mentions a possible alternative interpretation of occupational type, linked to the Venetian term bolzon ("dart, crossbow bolt"), which could allude to a maker or user of crossbows.

For his part, F. De Laurentiis reinforces the toponymic interpretation, noting that the surname is based on the place name Bolzano and that it indicates the geographical origin of the family.

Taken together, the various interpretations agree in pointing to a mainly toponymic origin, with a possible secondary occupational reading, and a distribution localised in the Venetian sphere.