Bouillon (French pronunciation: [bujɔ̃] ⓘ; Walloon: Bouyon) is a city and municipality of Wallonia located in the province of Luxembourg in the Ardennes, Belgium.

The municipality consists of the following districts: Bellevaux, Bouillon, Corbion, Dohan, Les Hayons, Noirefontaine, Poupehan, Rochehaut, Sensenruth, Ucimont, and Vivy.

The fortification of Bouillon Castle was, along with the County of Verdun, the core of the possessions of the Ardennes-Bouillon dynasty, and their combined territory was a complex mixture of fiefs, allodial land and other hereditary rights throughout the area.

The prince-bishops started to call themselves dukes of Bouillon, and the town emerged as the capital of a sovereign duchy by 1678, when it was captured from the prince-bishopric by the French army and given to the La Tour d'Auvergne family.

Books about Bouillon The town sits in a sharp bend of the river Semois (German: Sesbach, Walloon: Simwès, in France: Semoy) whose total length is 210 km.