The authors differ fundamentally in the origin of the surname. E. Rossoni derives it, directly or through affective forms, from the Latin cognomen Frolus —Frollo in vulgar Italian—, cited for example in the Vita di Mecenate of the Perugia poet Cesare Caporali (1531–1601). R. Brondolo, on the other hand, rejects that it comes from the dialectal adjective frol ("soft") and proposes instead a derivation from the name Matteo, through the forms Maffeo, Maffè, Fè, Fe-r-oll, with the sense of "little Matteo".

According to Rossoni, the surname presents multiple independent clusters of origin (ceppi), arisen in different regions without direct relation between them. The variant Frola is peculiar to the Canavese, in Piedmont, and to Montanaro, in the Turin area, with a possible secondary zone in Naples. Froli is located in the Pisa area. Frollini is peculiar to Rome. Frollo appears in a scarce way in Emilia-Romagna, the Marche, Lazio and Campania, with a zone in Venice. Frolo, extremely rare, could be from southern Italy. Frolli has a wide distribution in Italy.