The authors agree that this surname is of a toponymic nature, derived from the place name Casanova —literally "new house"— frequent in various areas of Italy. E. Rossoni notes that the surname is present throughout Italy, with greater concentration in the Belluno area, the Genoa area, the Romagna and the Bari and Naples areas. He points out that it could have originated as a nickname linked to some place name called Casanova in the Genoa, Caserta, Pavia, Vercelli, Como or Savona areas, or simply as a reference to "those of the new house". The variant Casanuova is very scarce.

E. De Stefani provides a more detailed perspective on the Alpine and northeastern area. He documents the surname from at least the end of the 13th century in localities of the province of Belluno —such as San Pietro di Cadore, Santo Stefano di Cadore, Cortina d'Ampezzo, Sospirolo and Cesiomaggiore—, as well as in Montebelluna and Venice. In the Carnia, he notes a notable presence in Ravascletto and its hamlet Zovello, linked to migrations documented from the Comelico. De Stefani also records that in German-speaking areas of the Alpine region the surname was translated as Neuhaus ("new house" in German), a phenomenon attested for Carnian merchants of the 18th century.