Saxe-Römhild (German: Sachsen-Römhild) was an Ernestine duchy in the southern foothills of the Thuringian Forest.

After the duke of Saxe-Gotha, Ernest the Pious, died on 26 March 1675 in Gotha, the duchy was divided on 24 February 1680 among his seven surviving sons.

The actual administration was left to the higher authorities in Gotha – the so-called Nexus Gothanus – because that was the residence of Henry's oldest brother, who ruled as Frederick I, Duke of Saxe-Gotha-Altenburg.

After the death of the childless Henry in 1710, his domains were divided among the four duchies – Saxe-Gotha-Altenburg, Saxe-Coburg-Saalfeld, Saxe-Meiningen and Saxe-Hildburghausen.

Saxe-Hildburghausen got the rest – the winery of Behrungen, the estate of Milz and the Echter properties.