Sankt Michael im Lungau is a market town in the district of Tamsweg, in the Austrian state of Salzburg. It lies in the Lungau, the southeastern region of Salzburg, and is one of the municipalities that make up the Tamsweg district.
As a market town (Marktgemeinde), it holds a status in Austrian administrative structure between a village and a city, a designation historically tied to its right to hold markets. The surrounding Lungau region is known for its alpine landscape and its position near the borders with Carinthia and Styria.