Thiers is a commune in the Puy-de-Dôme department of Auvergne in central France. With Ambert, Issoire and Riom, it is one of the department's four sub-prefectures. The district of Thiers consists of forty-three municipalities in six cantons. Its inhabitants are known as Thiernois or Bitords.
Thiers is a major historical centre of knife manufacturing, with about one hundred companies and a cutlery museum; seventy percent of French pocketknives, kitchen and table knives are manufactured in Thiers. The knowledge and craft of the Thiernois cutlers are over seven centuries old, and many of the old watermills that were used to manufacture Thiernois knives can still be seen in the Vallée des Rouets.
The city extends over 7 kilometres on a rocky spur overhanging the nearby mountains and the villages. It is divided into two sections: the lower city and the upper, medieval city.