E. Rossoni and V. Blunda differ on the origin of the surname.

Rossoni identifies it as a lineage of probable Lombard and Tuscan origin, later moved to Sicily. He derives it from the term alliatus ("ally", in the sense of a family allied to the Emperor).

Blunda, on the other hand, for the Sicilian variant derives it from the dialectal word alliàta ("area planted with garlic, garlic field"), belonging to the group of rural toponymic surnames. He notes that garlic cultivation, fundamental in Mediterranean cuisine, gave rise to rural microtoponyms that came to designate the families settled in those places. He adds that the variant Agliata keeps the standard Italian spelling as opposed to the Sicilian one with double l.