Monthey (French pronunciation: [mɔ̃tɛ]; Arpitan: Montê) is the capital of the district of Monthey in the canton of Valais in Switzerland.

The castle in the town center was built in 950 on a hill, the first houses of Monthey surrounded it. Monthey is first mentioned in 1215 as Montez. At the 13th century, the counts of Savoy owned the village and its area. In 1352, the count Amédée VI gave more freedom to the inhabitants. During the first part of the 14th century, there were several industries including silk production and grinding mills.