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

Thurgau is part of Eastern Switzerland. It is named after 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.