The authors agree that this surname derives from a medieval nickname or name linked to commercial activity, specifically from the occupational term mercante and its variants mercatante and mercadante.

E. De Felice notes that these names and nicknames spread in mercantile circles, sometimes with the auspicious value of good success in trade. He indicates that the form Mercante spread across Italy generally; Mercatante, of rare occurrence, appears in Tuscany; and Mercadante is documented in southern Italy and in Palermo.

E. Rossoni observes that the surnames of this family are fairly rare and are distributed irregularly across the Italian peninsula. He adds that Mercanti is more proper to northern Italy, while Mercantini shows an area of concentration in the province of Pesaro and another in Rome. As a notable figure, he mentions the poet and man of letters Luigi Mercantini, born in the 19th century at Ripatransone, in the province of Ascoli Piceno.