The Murg is a 34.1 kilometres long tributary of the Thur in Switzerland. It rises in the canton of St. Gallen, flows through the canton of Thurgau, and joins the Thur near Warth.
Along its route, the river flows through the communities of Mosnang, Fischingen, Sirnach, Münchwilen, Wängi, Stettfurt, Matzingen and Frauenfeld. Between Münchwilen and Frauenfeld the river is closely followed by the Frauenfeld–Wil railway line.
