Sankt Andrä im Lungau is a municipality in the district of Tamsweg, in the state of Salzburg, Austria. It lies in the Lungau, the southeastern region of Salzburg known for its alpine landscape and rural character.
As a municipality, it is one of the smaller administrative units within the Tamsweg district, which covers the Lungau and is the state's southernmost district. The area is part of Austria's Alpine zone, and the surrounding terrain is dominated by mountains and valleys typical of the Lungau.
Its status as a municipality places it within Austria's system of local government, with the district of Tamsweg serving as the intermediate administrative level between the municipality and the state of Salzburg.