The authors agree that this surname is of Sicilian origin and was formed from place names of the island. E. De Felice notes that it derives from the place names Militello Rosmarino, in the province of Messina, and Militello in Val di Catania, in the province of Catania. E. Rossoni agrees and specifies that the surname arose from nicknames linked to those same places.

F. Miranda broadens this information with etymological data: Militello in Val di Catania would go back to the Latin forms Mellis Tellus or Miletum Tellus, while Militello Rosmarino would correspond to the old Meleto, a term that designated an "apple field". He adds that Sant'Agata di Militello belonged to the territory of the prince of Militello, which reinforces the historical weight of the place name.

Miranda further documents a variant, Miritello, generated with certainty by a transcription error, present in some Sicilian municipalities of the Catania area and of the Enna area, such as Nicosia, Catenanuova and Troina. The surname is concentrated in Sicily, with a presence in all its provinces, although it also appears in other regions of Italy.