According to the sources cited below, this surname originates from the transformation into a surname of the medieval Latin name Piccolus, attributed to an unknown first bearer. F. Miranda also identifies two alternative explanations: it may derive from a nickname referring to the short stature of its bearer, or from the Late Latin term piccolus, denoting a soldier who carried a pike. F. De Laurentiis adds that the surname can be considered a variant of a broader group of surnames related to the Italian adjective meaning "small."

Miranda notes that the surname is found throughout Italy, with a particularly strong presence in the region of Campania, as well as in specific, localized areas of Veneto, Apulia, Lombardy, Sicily, Calabria, Lazio, and Piedmont. Within Sicily, it is distributed across all provinces, with a notable concentration in the areas of Messina, Catania, Palermo, and Trapani.

It is also recorded that Italian surnames of this type were often anglicized in the United States, where Piccolo was rendered as "Little."