The authors agree on the Greek origin of the surname, although they differ in the details of the etymon and in the geographical distribution they privilege. G. Rohlfs links it with the Greek-Byzantine surname Kalèas, documented in Athens, and notes its presence in the Reggio Calabria area —especially around Mèlito and the Aspromonte—, with an extension towards the Cosenza and Catanzaro areas, and also in Sicily.

V. Blunda derives it from the Greek Calèas and highlights its Sicilian rooting, where the spelling with double ll represents the Italianization of the original form. Blunda notes that this etymon is parallel to the one that supports the surname Calìa, from which Callea is distinguished precisely by that double consonant.