Saint-Vallier (French pronunciation: [sɛ̃ valje] ⓘ; Arpitan: Sent-Valiér) is a commune in the Drôme department in southeastern France.

It has a number of factories and industrial units making aviation parts, ceramic insulators, nuclear taps, tiles and stationery.

It originally housed a religious community of monks but was rebuilt in the nineteenth century by Comte Dupeyroux de Salmagne.

In the eighteenth century, feldspar and kaolin were found in the area and an industry grew up making hard-paste porcelain fired at a high temperature.

She became the favourite of Henry II of France and wielded much power until he was fatally wounded in 1559 in a jousting tournament and his widow, Catherine de' Medici, expelled her from the court.