Sarnonico (Sarnónec in local dialect) 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 696 and an area of .
The municipality of Sarnonico contains the frazione (subdivision) Seio.
Sarnonico borders the following municipalities: Brez, Cavareno, Dambel, Fondo, Malosco, Romeno, Ronzone, Ruffré-Mendola, Eppan and Kaltern.