F. Miranda identifies this surname, along with its variants (Grigoletti, Grigoletto, Grigolli, Grigollo, Griguoli, Griguolo), as deriving — directly or through dialect hypocoristics — from the medieval Latin name Grigolus. This in turn represents a hypocoristic form, characteristic of northeastern Italy (in the regions of Veneto, Friuli-Venezia Giulia, and Trentino-Alto Adige) and of the historical territory of the Republic of Venice, of the name Gregorius, of Greek origin, carrying the meaning "quick, swift in action."

G. P. Holmes concurs in tracing the surname to the given name Gregorio, derived from medieval Greek. It is also recorded that the surname stems from the Greek verb ghregorein, meaning "to be smart, intelligent" — a nuance that complements Miranda's etymological account.

According to Miranda, the surname is found across several Italian regions, including Veneto, Sicily, Lombardy, Piedmont, Liguria, Emilia-Romagna, Trentino-Alto Adige, Lazio, and Tuscany. In Sicily, it appears in the area of Palermo (including Carini, Bagheria, and Termini Imerese), the area of Catania (Bronte and Biancavilla), the area of Enna (Pietraperzia and Nicosia), and the area of Agrigento (Canicattì).