Schloss Köthen is a palace (schloss) in Köthen (Anhalt), Germany. Begun as a castle, it was protected by a moat. It was the residence of the Princes and Dukes of Anhalt from 1244 to 1847, and now belongs to a foundation for the preservation of sites in Saxony-Anhalt. The composer Johann Sebastian Bach was employed there by Leopold, Prince of Anhalt-Köthen. The palace is one of the locations for Köthen's biannual Bach festival.