The surname Besana is of toponymic origin and is clearly linked to Lombard territory. According to E. De Felice, it derives from the place name Besana in Brianza (Milan), and is particularly common in this area, which reflects the medieval practice of identifying people by their place of provenance.

Along the same lines, E. Rossoni broadens the possible derivations, noting that the surname can also originate from other nearby place names, such as Besano (Varese area), in addition to Besana in Brianza. This multiplicity of geographical references reinforces the idea of a local origin linked to different localities with similar names in Lombardy.

From the point of view of distribution, E. Rossoni indicates that Besana is typical of the north of the Milanese area and of areas such as Lecco, Como and Varese, while Besani is a very rare variant concentrated in the Varese area. Taken together, both interpretations agree in pointing to a strictly toponymic origin, linked to the Brianza region and neighbouring areas.