E. De Stefani notes that the surname comes from the Friulian and Venetian term barbàn, meaning "uncle" and also used as a form of respect towards the elderly. It would have originally functioned as a nickname applied to the uncle who took charge of a family unit, or as a deferential form of address towards an old man, until it became a surname. De Stefani indicates that the same etymon gave rise to related surnames in other regions: Barbano in Piedmont, Liguria and Puglia, and Barbani in Tuscany.

E. Rossoni proposes two routes of origin: the derivation from the medieval Latin term barbanus ("uncle"), documented in a deposition of witnesses of the year 1180 in Lodi, or that of a nickname referring to someone characterised by his prominent beard. Rossoni agrees with De Stefani on the main semantic root, although he adds this second possibility and provides the medieval documentary support.

As for the geographical distribution, both authors agree that Barban is a surname typically peculiar to the Veneto, concentrated in the Vicenza, Padua, Venice and Treviso areas, with sporadic presence in Verona, Rovigo and Friuli. De Stefani adds its historical attestation in the Carnia, a mountainous area of northern Friuli in the province of Udine.