The two scholars consulted agree on the Greek origin of this surname but differ in scope and detail. E. Rossoni considers it very rare and specific to the province of Reggio Calabria. He traces it to a nickname derived from the Greek word megalos ("great," "stout," "tall"), arising from the imposing physical characteristics of the ancestor who first bore it. As evidence of its early transformation into a surname, Rossoni cites a record from the second half of the 17th century at Bovalino, in the province of Reggio Calabria, where a certain Gioseppe Megali appears as a witness in a deed.

G. Rohlfs broadens the geographical scope considerably. He classifies this surname as Greco-Byzantine in origin and documents it in Catanzaro, Cosenza, and Reggio Calabria, as well as in localities within their provinces, including Squillace, Catafòrio, and Cittanova. He further notes its presence in the Calabro-Lucanian area, specifically at Trebisacce, and records it as well in the areas of Naples and Sicily. Like Rossoni, Rohlfs identifies the etymon as the Greek μεγάλος ("great"), and he regards Megale as a sister form of Megali.

It should be noted that the source Surnames in Italy connects this surname instead to the first name Michele, derived from the Hebrew Micha'el, meaning "who is as powerful and great as God." This interpretation diverges entirely from those of Rossoni and Rohlfs and is not corroborated by the other sources consulted.