E. De Felice notes that the surname has as its base the name of the celebrated sultan of Egypt and Syria Saladin (in Arabic Ṣalāḥ ad-dīn, "justice of the religion"), who died in 1193. He recalls that Dante placed him among the great spirits of Limbo. He documents its greater diffusion in the south and Sicily, where it probably arrived with the Crusades and the Arab-Norman domination.

A. Bongioanni specifies that the name was popularized by the medieval novelists and became a surname in Piedmont and central Italy.

E. Rossoni agrees on the origin and suggests that the surname would derive from nicknames related to the name of Salah El-Din Al-Ayubi, called Saladin (1169–1250), the celebrated founder of a great Muslim state and leader of the army opposed to the Crusaders. He documents cases already in the 13th century, in a deed of Luni, in the La Spezia area, of 1279.

Rossoni suggests as an alternative hypothesis a derivation from the Italianization of the Arabic surname Salah El-Din, which would mean "prayer (or praise) of the religion." He further distinguishes the forms: for De Saladino he identifies two zones, one in western Sicily and another in the Catanzaro area; Salardino, very infrequent, would seem to be Sicilian —of Palermo and Misilmeri, in the Palermo area— and would be a variation of the former.