E. Rossoni notes that these surnames would derive from the medieval Latin name Colombanus. He recalls Saint Columbanus (540?–615), a monk of Irish origin who in the year 600 founded the abbey of Bobbio, in the Piacenza area. Rossoni also considers possible a derivation from the place name San Colombano, located in the Lodi area. As for its distribution, he identifies an area in the south of the Milan area and in the Lodi area, and another in the Ferrara area; Colombano, for its part, is typical of western Piedmont.

F. De Laurentiis presents it as a northern derivative of Colombo, which reflects the prestige and the cult of Saint Columbanus, the Irish monk whose name was Latinised as Columba or Columbanus. De Laurentiis adds that some surnames of this family can derive directly from the place name Colombano, in the Rovigo area.