The Turin Metropolitan Railway Service, simply known as SFM, is a commuter rail system serving the metropolitan area of Turin, Italy. The system comprises 8 lines operated by Gruppo Torinese Trasporti and Trenitalia, serving 93 stations.

The Gruppo Torinese Trasporti (GTT) is a public benefit corporation responsible for public transportation in the provinces of Alessandria, Cuneo, Asti and the Metropolitan City of Turin. It was created in 2003 from the merge of ATM and SATTI, the latter responsible for railway connection in the province of Turin as well as for the Turin metro. GTT is now wholly owned by the Turin City Hall.