Rorschach is a municipality in the Wahlkreis (constituency) of Rorschach in the canton of St. Gallen in Switzerland.
It is south of the Lake Constance (German: Bodensee)
As of 2003, it had a population of 9000 (approx.) and a surface of 1.78 km².
The place was first mentioned in 850 as Rorscahun. In 947, Otto I granted the abbot of St. Gall the right for markets, coinage and tariffs at Rorschach.
Sights include the Kornhaus, lake promenade, aviation museum in Altenrhein, the abbey Mariaberg, as well as the St. Anna, Wartensee, Sulzberg and Wartegg castles.
The city is governed by a city council, headed by mayor Thomas Müller (CVP, elected 2003), and a parliament.