Schwarzach is a municipality in the Austrian state of Vorarlberg, in the far west of the country. It lies in the Vorarlberg Rhine Valley, the broad lowland along the Alpine Rhine that forms the border with Switzerland, within the district of Bregenz.
The municipality is part of the Rhine Valley settlement belt, a string of towns and villages between Lake Constance to the north and the Montafon valley to the south. This places Schwarzach close to the provincial capital, Bregenz, and to the town of Dornbirn, both of which lie within a short distance along the valley.
Like much of Vorarlberg, the area around Schwarzach combines valley-floor settlement with nearby Alpine terrain, and the municipality belongs to a region known for its textile and manufacturing industries as well as its mountain landscape. The Rhine Valley location also gives the municipality good road and rail connections within Vorarlberg and toward neighbouring Switzerland and Germany.