Galati Mamertino is a comune (municipality) in the Province of Messina in the Italian region Sicily, located about 120 kilometres (75 mi) east of Palermo and about 70 kilometres (43 mi) west of Messina. As of 31 December 2004, it had a population of 3,026 and an area of 39.0 square kilometres (15.1 sq mi).
The municipality of Galati Mamertino contains the frazione (subdivision) San Basilio.
Galati Mamertino borders the following municipalities: Frazzanò, Longi, San Salvatore di Fitalia, Tortorici.