Sassofeltrio is a comune (municipality) in the Province of Rimini in the Italian region Emilia-Romagna, located about 145 km southeast of Bologna and about 21 km south of Rimini. On 24-25 June 2007 Sassofeltrio, alongside the nearby comune of Montecopiolo, voted in a referendum to detach from neighboring Province of Pesaro and Urbino in Marche region in favor of Province of Rimini in Emilia-Romagna, it came into effect 14 years later on 17 June 2021. Sassofeltrio borders the following municipalities: Chiesanuova (San Marino), Faetano (San Marino), Fiorentino (San Marino), Gemmano, Mercatino Conca, Montegiardino (San Marino), Monte Grimano, Montescudo, San Leo, Verucchio.

Twin towns