Bad Kösen (German: [baːt ˈkøːzn̩] ) is a spa town on the Saale river in the small wine-growing region of Saale-Unstrut, Germany. It is a former municipality in the Burgenlandkreis district, in Saxony-Anhalt. Bad Kösen has a population of around 5,300. Since 1 January 2010, it has been a Stadtteil (part) of the town of Naumburg.