Sierre (sjɛʁ; Siders, zidɐs; Siérro, ˈʃiʁo) is the capital municipality of the district of Sierre, located in the canton of Valais, Switzerland. It has a population of 16,332.
Sierre is nicknamed City of the Sun (Cité du Soleil) for its average of 300 days of sunshine a year.
It is the last official French-speaking city in Valais before the French–German language border of the canton located at the forêt de Finges, a few kilometres after the town. A German-speaking minority lives in Sierre, counting for around 8% of the population.
Sierre was first mentioned around 800 as Sidrium, though a 12th-century document refers to the village being founded in 515. In 1179 it was mentioned as Sirro and in 1393 as Syder.
The area around the modern town, especially Gerunden hill, was settled very early. Archeological sites on the Gerunden hill have produced neolithic objects and grave goods (including a polished stone ax), Bronze Age weapons and jewelry, Early Iron Age objects, and Roman era inscriptions, jars, jewelry, and coins. A soapstone pot from the Early Middle Ages and a gold signet ring with the name Graifarius from the 6th century have also been found. Other sites on nearby hills and near the chapel of Saint-Ginier, the Château de Villa, the churches of Sainte-Croix, Grands-Prés, Muraz, Glarey and Bernunes have yielded up graves originating from the Bronze Age to the Carolingian era. In Grands-Prés there is a fire pit from the beginning of the Late Iron Age (5th–6th century BC).
During the Roman era it appears that there was no major population center, but rather several scattered groupings of separate, upper-class dwellings. Under the chapel of Saint-Ginier, the remains of a Roman-era house or estate have been discovered. Other Roman ruins have been found near the Château de Villa, in the church of Sainte-Croix (small terraced bath), in Grands-Prés by Muraz another house and in Gerunden the remains of buttress reinforced masonry indicate that a public or government building once stood there.