Castelfondo () is a comune (municipality) in Trentino in the northern Italian region Trentino-Alto Adige/Südtirol, located about north of Trento.
As of 31 December 2004, it had a population of 624 and an area of .
Castelfondo borders the following municipalities: Brez, Fondo, St. Pankraz, Unsere Liebe Frau im Walde-St. Felix and Laurein.