The surname Dutto has a notable concentration in the province of Cuneo, where it occupies 8th place among the most frequent, with 789 bearers distributed in 60 municipalities. Its main foci are in Cuneo (309 ≈ 1.5%), Boves (151 ≈ 5.5%), Peveragno (53 ≈ 2.3%), Borgo San Dalmazzo (32 ≈ 0.8%) and also in Margarita and Beinette, although with smaller figures.

It is considered that Dutto was formed by aphaeresis of an affective variant of the name Giacomo, very widespread in western Piedmont. The process would be thus:

Giacomo → Giacomandù (affective dialectal form) → Giacomandutto → Dutto

Other hypotheses on the surname

The first documented spellings, such as "Dutus" and "Dudus" (years 1268–1288) and "de Dodis" (1279), let glimpse influences both Germanic (from the name Duda, root dod, later Italianised into Duasco) and Latin (Doctus, "erudite"). Nevertheless, the hypothesis of an origin in (aquae) ductus (aqueduct) must be discarded, since that lineage corresponds to the surname Doccio and its derivatives.

There are also a couple of related surnames and historical variants that reflect this same dialectal evolution. Dutta would be the feminine form, and Dutti appears very rarely in Ghedi (Brescia), but shares the same scheme of aphaeresis of the hypocoristic of Giacomo.

On the other hand, Comandù —recorded already in 1708 with a father Comandù in the mission of San Javier in Mulegé (Mexico) and in 1782 with the painter Giovanni Comandù in Rivoli (Turin)— comes from the same dialectal chain:

Giacomo → Giacomand → Giacomandù → Comandù

As a whole, Dutto exemplifies a typical Piedmontese surname of "family capital": it originates from the affective deformation of a common proper name, preserves documented medieval forms and maintains, to this day, a strong local imprint in Cuneo and its surroundings.