Silvano d'Orba is a comune (municipality) in the Province of Alessandria in the Italian region Piedmont, located about southeast of Turin and about south of Alessandria. As of 31 December 2004, it had a population of 1,856 and an area of .
The municipality of Silvano d'Orba contains the frazioni (subdivisions, mainly villages and hamlets) Valle Cochi, Pieve, Bacchetti, Guastarina, Pagliara, Villa, Milanesi, Setteventi, Ravino, Bolla, Pagliaccia, Bordini, Pianterasso, Bessica, Prieto, Castagnola, Caraffa, and Passada.
Silvano d'Orba borders the following municipalities: Capriata d'Orba, Castelletto d'Orba, Lerma, Ovada, Rocca Grimalda, and Tagliolo Monferrato.
Adorno Castle is located in the comune.