The Duchy of Saxe-Jena was one of the Saxon Duchies held by the Ernestine line of the Wettin Dynasty.

Established in 1672 for Bernhard, fourth son of Wilhelm, Duke of Saxe-Weimar, Saxe-Jena was reincorporated into Saxe-Weimar on the extinction of Bernhard's line in 1690.

Reincorporated into Saxe-Weimar