Rocchetta Tanaro is a comune (municipality) in the Province of Asti in the Italian region Piedmont, located about southeast of Turin and about southeast of Asti. As of 31 December 2004, it had a population of 1,454 and an area of .
Rocchetta Tanaro borders the following municipalities: Belveglio, Castello di Annone, Cerro Tanaro, Cortiglione, Masio, Mombercelli, and Rocca d'Arazzo.
Rocchetta Tanaro is twinned with: