E. De Felice, E. Rossoni and F. De Laurentiis agree that Bello and its many related forms —such as Belli, Bellini, Bellomo and Bellocchio— derive from the medieval name or nickname Bello, based on the Italian adjective bello (“beautiful”, “handsome”). Originally, it was used either to describe a person of attractive appearance or as an auspicious name expressing the wish that a child would grow up healthy, pleasant and admired.

E. De Felice notes that the name is documented from the early Middle Ages and gave rise to a wide variety of surname forms throughout Italy. These include patronymic forms with De or Di, article-based forms such as Lo Bello and La Bella, Slavic-influenced variants such as Bellich in Venezia Giulia, and numerous derivatives, among them the widespread surname Bellini, especially common in areas such as Milan and Florence. Other variants, including Bellomo and Bellocchio, reflect regional developments of the same onomastic root.

F. De Laurentiis confirms that the surname originated from the personal name or nickname Bello/Bella, associated both with physical appearance and with an auspicious meaning. E. Rossoni further suggests that the surname may derive from the medieval name of good omen Bellus, already documented in the 12th century through records such as the notary Petrus Bellus in the Milan area. Rossoni also observes that the variant Belli is more common in central and northern Italy, while Bello is particularly widespread in southern Italy, the Triveneto, Piedmont and Sicily.

Overall, the surname Bello belongs to a broad family of Italian surnames rooted in the concept of beauty and positive personal qualities. Over time, what began as a descriptive or auspicious name became a hereditary surname with numerous regional variants throughout Italy.