The authors agree that the surname is of Greek-Byzantine origin, preserved in southern Italy through the cultural and linguistic transmission of that historical period.

G. Rohlfs documents it in the provinces of Catanzaro and Reggio Calabria, and compares it with the Greek surname βαχλᾶς. He also notes that the form with the Greek ending –άδες gave rise to the place name Bagaladi, a municipality in the province of Reggio Calabria. In Sicily it appears as Bacalà or Bagalà, and in the Neapolitan area as Baccalà.

V. Blunda specifies the etymon as the Greek personal name or nickname bachlàs, transmitted by Byzantine route in southern Italy. He adds that in the Italianised spelling of the surname, the Greek consonant ch was resolved as g, which explains the predominant form Bagalà.