The name appears first in 1185 as «de Tremosino», in 1380 as «de Tremosigno». The place name is believed to derive from an ancient personal name, Tremusina, perhaps of Etruscan origin. Formally, Tremosine could also derive geo-morphologically from the Italian word “tramoggia”, hopper.
Tremosine appears with the title of «Comune» (Municipality) on 12 May 1268. The most ancient known sample of the original coat of arms is found on the side-door of the church of San Giovanni Battista, in Pieve, and shows three curly-haired human heads portrayed in profile, marked with the letters «C» and «T», the initials for Comunitas Tremoseni.
The current coat of arms of the town is an azure shield with three mountains, the central one bearing a Latin cross, rising from an argent plain with two azure wave bands and bearing above everything the silver motto “ET TU VIATOR VALE”.