According to F. De Laurentiis, Barbato is a surname derived from medieval nicknames based on the word barba (“beard”). Such nicknames were commonly used to identify a person who wore a distinctive beard or was known for a particular type of facial hair. In medieval society, the beard was often associated with maturity, authority, wisdom, and social status, making it a frequent source of personal nicknames.

V. Blunda proposes a different but related origin. He traces the surname to the Greek personal name Barbàtos, preserved in southern Italy through Byzantine influence. This name is likewise connected to the root meaning “beard” and later became established as a hereditary surname, particularly in Sicily. According to Blunda, the modern form Barbato represents the Italianized spelling of this older Greek-Byzantine name.

Although they differ in the path of development, both interpretations share the same underlying root associated with the beard. De Laurentiis emphasizes a medieval nickname of general Italian usage, while Blunda highlights a Greek-Byzantine personal name that survived in southern Italy.

Overall, Barbato is a surname linked to the concept of the beard, either through a descriptive medieval nickname or through the Byzantine personal name Barbàtos, both reflecting a characteristic that became a hereditary family name.