Triesen (; dialectal: Tresa) is the third largest municipality in Liechtenstein. It contains several historic churches dating from the fifteenth century. It also has a weaving mill from 1863 that is considered a historical monument. The population is around 5,275.
The municipality includes the highest point of Liechtenstein, the Grauspitz, at above sea level. Triesen's lowest point is the Liechtenstein inland canal, at above sea level. It is located between the Liechtenstein municipalities of Balzers, Schaan, Triesenberg, and Vaduz. Triesen also borders several Swiss municipalities: Wartau (in St. Gallen), along with Maienfeld and Fläsch (both in Grisons). The municipality of Triesen contains the alpine pastures of Lawena, Wang, and Valüna.
The settlements of Triesen, as the state archaeologists have found during excavations, were destroyed in natural disasters. The detailed picture of the place Triesen shows that all settlement phases were terminated by the forces of nature. It has been demonstrated that the settlements of the Bronze Age and the Iron Age were repeatedly destroyed by floods and landslides.
The coat of arms of the municipality of Triesen, granted in 1956, consists of a shield with three superimposed silver scythes on a blue background.
Triesen is locally administered by the mayor and a 10-person municipal council, elected every four years since 1975. The incumbent mayor is Daniela Erne, since 2019.
Attractions in the Triesen area include: