San Martin de Tor (Italian: San Martino in Badia [sam marˈtiːno im baˈdiːa]; German: St. Martin in Thurn [saŋkt ˈmartɪn ɪn ˈtʊrn]) is a comune (municipality) and a village in South Tyrol in northern Italy, located about 45 kilometres (28 mi) northeast of the city of Bolzano.

As of 30 November 2010, it had a population of 1,726 and an area of 76.5 square kilometres (29.5 sq mi).

San Martin borders the following municipalities: Badia, Brixen, Corvara, La Val, Lüsen, Mareo, Santa Cristina Gherdëina, Sëlva and Villnöß.

The municipality contains the frazioni (subdivisions, mainly villages and hamlets) of Antermëia (Antermoia/Untermoi), Lungiarü (Longiarù/Campill), and Picolin (Piccolino/Pikolein).

The tower is a reference to Tor Castle and resumes the insignia of a noble family; the cross over the mountains recalls that the town was once the Courts.