Enghien (French: [ɑ̃ɡjɛ̃] ⓘ; Dutch: Edingen [ˈeːdɪŋə(n)] ⓘ; Picard: Inguî; West Flemish: Enge) is a city and municipality of Wallonia located in the province of Hainaut, Belgium.

Enghien gave its name to a French duchy and to the commune of Enghien-les-Bains, a suburb of Paris, due to a complex series of family successions: in 1487, Mary of Luxembourg (d. 1547), the only heir of Peter II of Luxembourg (d. 1482), Count of Saint-Pol-sur-Ternoise and member of one of the branches of the House of Luxembourg, married François de Bourbon-Vendôme (d. 1495), the great-grandfather of King Henry IV of France.

Mary of Luxembourg brought as her dowry the fief of Condé-en-Brie (Aisne département, France) and the county of Enghien, among others.

These fiefs passed to her grandson Louis I de Bourbon, Prince de Condé, uncle of King Henry IV of France, who started the line of the Princes of Condé, the famous cadet branch of the French royal family.

However, the necessary registration process was not completed, so the title became extinct at the death of Louis I de Bourbon in 1569.