Goldach is a municipality in the Wahlkreis (constituency) of Rorschach in the canton of St. Gallen in Switzerland.

Of the rest of the land, 51.9% is settled (buildings or roads) and the remainder (2.3%) is non-productive (rivers or lakes).

It is located on the road between Rorschach and St. Gallen and stretches from Lake Constance to the Rorschacherberg.

Of the foreign population, (as of 2000[update]), 128 are from Germany, 625 are from Italy, 481 are from ex-Yugoslavia, 129 are from Austria, 69 are from Turkey, and 218 are from another country.

[8] The age distribution, as of 2000[update], in Goldach is; 935 children or 11.1% of the population are between 0 and 9 years old and 1,029 teenagers or 12.2% are between 10 and 19.

[11] From the 2000 census[update], 4,729 or 56.0% are Roman Catholic, while 2,308 or 27.3% belonged to the Swiss Reformed Church.

[8] The Schlosslandschaft Rorschach / Alter Rhein, a number of castles in a region along the Rhine river, is designated as part of the Inventory of Swiss Heritage Sites.

The Schlosslandschaft is shared between Berg, Goldach, Mörschwil, Rheineck, Rorschacherberg, St. Margrethen, Steinach, Thal and Tübach.