The three sources present largely convergent but partially distinct contributions. E. Rossoni traces this surname to the medieval name Leo (Leonis), the Latin equivalent of Leone ("Lion"), and notes that it is found throughout southern Italy, Sicily, and southern Sardinia. F. De Laurentiis likewise connects it to the Latin leo, "lion," adding that the name could have functioned both as a given name and as a metaphorical nickname alluding to the animal itself. De Laurentiis further observes that this is an ancient surname, as many families adopted an animal as their emblem, venerating it as a symbol of origin and protection.

P. Durante proposes a different etymology, suggesting a Greek origin from the given name León. It is also noted that the surname derives from the first name Leone, meaning "lion." While the Latin and Greek roots are formally distinct, both point ultimately to the same underlying meaning.