E. De Felice, E. Rossoni and N. Bergamo agree on the origin of the surname from the name Sergio.

De Felice specifies that it continues the Latin cognomen of the republican period Sergius —passed to the Greek Sérgios and from there extended to Eastern Europe and Asia Minor—, consolidated in Christian and medieval times by the prestige and cult of saints and popes of this name. He adds that in the south it was reinforced by the dynasties of the dukes of Amalfi and Naples, in which the name Sergio was traditional from the 9th to the 12th century.

Rossoni derives it from the Latin gens Sergia, documented in Cicero's first Catilinarian. He recalls among the historical bearers of the name Pope Sergius I, elected in the year 687. Rossoni distinguishes the forms: Sergi has several lines in the south of Sardinia, in the area of the strait between the Reggio Calabria and Messina areas, in the Salento and in Rome; Sergio is typical of the south of the peninsula.

Bergamo records it as a surname of Greek origin, taken from the given name.