Sankt Märgen (Low Alemannic: Sankt Märge) is a German municipality in the middle of the Black Forest, which belongs to the district of Breisgau-Hochschwarzwald.

The Kurort (spa town) is located around 25 km east of Freiburg im Breisgau.

The village territory extends from the Thurner Plateau in the south to the eastern foothills of Kandel to the north, which are between 570 and 1132 meters high.

To the east and west its boundaries are marked by deep valleys.

Between 1115 and 1118 the Augustinian monastery of Maria-Zell auf dem Schwarzwald was established by Count Bruno von Haigerloch-Wiesneck, Chancellor of Henry V and Provost of Straßburg, as competition to the Zähringen-founded Benedictine monastery of St. Peter auf dem Schwarzwald.