St. Martin in Passeier (; ) is a comune (municipality) and a village in the Passeier Valley in South Tyrol, northern Italian, located about northwest of Bolzano.
As of 30 November 2010, it had a population of 3,137 and an area of .
The municipality contains the frazioni (subdivisions, mainly villages and hamlets) Saltaus (Saltusio), Quellenhof (Sorgente), Ried (Novale), Kalmtal (Valclava), Christl (Cresta), Flon (Vallone), and Matatz (Montaccio),
St Martin in Passeier borders the following municipalities: Moos in Passeier, Riffian, and St Leonhard in Passeier.
The coat of arms is argent and azure party per pale; in the first part is an azure halberd, in the second half an argent wheel, with four rays. The halberd symbolizes the privileges of the free farmers, while the wheel the village laboriousness.
According to the 2024 census, 98.77% of the population speak German, 1.16% Italian and 0.06% Ladin as first language.
In 2017 it was the venue for the Linuxbierwanderung.