Thurgau (German: [ˈtuːrɡaʊ] (listen); French: Thurgovie; Italian: Turgovia; Romansh: Turgovia), anglicized as Thurgovia, more formally the Canton of Thurgau, is one of the 26 cantons forming the Swiss Confederation. It is composed of five districts and its capital is Frauenfeld.

Thurgau is part of Eastern Switzerland. It is named for the river Thur, and the name Thurgovia was historically used for a larger area, including part of this river's basin upstream of the modern canton. The area of what is now Thurgau was acquired as subject territories by the cantons of the Old Swiss Confederacy from the mid 15th century. Thurgau was first declared a canton in its own right at the formation of the Helvetic Republic in 1798.

The population, as of December 2020, is 282,909. In 2007, there were a total of 47,390 resident foreigners, constituting 19.9% of the population.