Saint-Vallier is a town the Drôme department (Rhone-Alpes Region) in south-eastern France.
It is approximately 60 miles south of Lyon and 16 ¾ miles north of Valence (the department capital) on the eastern bank of the Rhone river. St Vallier is 280 miles from Paris and 422 Miles from Calais.
The Galaure river flows northwest through the southern part of the town, crosses the town, then flows into the Rhone, which forms the town's western border. The town has a population of just over 4000 (2008).
The town is known as the place where Diane de Poitiers, one of the most well-known of French royal mistresses, was born in 1499.
The area is renowned for it’s wine production and the growing of apricots.