Châtelet (French pronunciation: [ʃatlɛ] ⓘ; Walloon: Tcheslet) is a city and municipality of Wallonia located in the province of Hainaut, Belgium.

The first settlers of the site of Châtelet, dating from paleolithic times, were attracted by the ford on the river, the nearby wooded areas and flint-rich highlands.

The protection later afforded by the Prince-Bishopric of Liège made the city into an important administrative, cultural, and economic centre, which could boast four annual trade fairs and a weekly cattle market.

While Châtelet's economy was dominated by artisanal guilds and trade, that of its neighbours, including Châtelineau and Bouffioulx, remained mostly agricultural.

The 18th century first witnessed the gradual shift of the regional economic power from Châtelet to the newly founded neighbouring city of Charleroi.