Kaltbrunn is a municipality in the Wahlkreis (constituency) of See-Gaster in the canton of St. Gallen in Switzerland.

Of the rest of the land, 7.8% is settled (buildings or roads) and the remainder (3.1%) is non-productive (rivers or lakes).

The blazon of the municipal coat of arms is Gules, St. George armoured, cloaked and helmeted Azure with a shield Argent a cross Gules and with lance Sable riding a Horse Argent killing the Dragon Sable[5] Kaltbrunn has a population (as of 31 December 2020) of 4,976.

Of the foreign population, (as of 2000[update]), 44 are from Germany, 140 are from Italy, 418 are from ex-Yugoslavia, 18 are from Austria, 37 are from Turkey, and 107 are from other countries.

[8] The age distribution, as of 2000[update], in Kaltbrunn is; 542 children or 14.7% of the population are between 0 and 9 years old and 620 teenagers or 16.8% are between 10 and 19.

[4] Out of the total population in Kaltbrunn, as of 2000[update], the highest education level completed by 907 people (24.6% of the population) was Primary, while 1,174 (31.8%) have completed Secondary, 266 (7.2%) have attended a Tertiary school, and 176 (4.8%) are not in school.

[11] From the 2000 census[update], 2,499 or 67.7% are Roman Catholic, while 377 or 10.2% belonged to the Swiss Reformed Church.