After the first performance on 14 October 1801, in modest surroundings, a "Theater Stock Company" was founded in 1805 to support a local professional theatre group.

When they needed a larger place for their performances, the architect Johann Christoph Kunkler built a theater into which the group moved in 1857.

The current building was designed by the Swiss architect Claude Paillard and inaugurated with Beethoven's Fidelio on 15 March 1968.

With the construction of the new building, the stock company was replaced by a consortium with participation of the town of St. Gallen and its canton.

Among them, in 2009, the theater featured the world premiere of The Count of Monte Cristo, a musical by Frank Wildhorn.