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

Uznach is first mentioned in 741 as Uzinaa in a grant from a noble lady at Benken Abbey to the Abbey of Saint Gall . It was also mentioned later as both Uzinaha and Uzzinriuda.

In the late 12th Century, the village was transferred from the Abbey of St. Gallen to the Counts of Toggenburg.