The authors agree that the surname derives from the given name of Germanic origin composed of two elements: hroth (glory, fame) and berht / bertha (bright, illustrious). F. Miranda details the chain of Latinizations of the original name: Hrodebert, then Rudpertus, Rupertus and Rihpertus, until reaching the form Roberto.

Miranda further notes that the surname has numerous variants: Robertello, Robertelli, Roberti, Robertini, Robertino, Robertone, Robertuccio and Robertucci, all derived directly or through dialect modifications, hypocoristics or augmentatives. A. Bongioanni adds that Roberto concurs with Alberto, Lamberto and other similar names in the formation of disyllabic surnames and their derivatives, such as Berti, Bertelli and Bertini.

Bongioanni supplies a fact of philological interest: the Friulian humanist Robortelli Latinized his surname in this way to bring it closer to the Latin robur. Miranda indicates that the surname is distributed widely throughout Italy, with a greater presence in Apulia and Campania, and more specific areas in Piedmont, Lombardy, Lazio, Calabria, Sicily, Liguria, Emilia-Romagna, Veneto and Tuscany.

V. Blunda highlights the historical figure of Robert Guiscard (c. 1015–1085), the Norman duke of Apulia, Calabria and Sicily, whose conquest of the far south of Italy consolidated the Norman presence and laid the foundations of the Kingdom of Sicily under Roger II in 1130.