San Martino in Rio

San Martino in Rio (Reggiano: Sân Martèin Grand) is a comune (municipality) in the Province of Reggio Emilia in the Italian region Emilia-Romagna, located about 50 km northwest of Bologna and about 12 km northeast of Reggio Emilia.

San Martino in Rio borders the following municipalities: Campogalliano, Correggio, Reggio Emilia, Rubiera.