Ernest I, Duke of Saxe-Gotha

Ernest I
Ernest I
Duke of Saxe-Gotha and Altenburg
Reign	14 April 1672 – 26 March 1675
Successors	Frederick in Saxe-Gotha-Altenburg; Albrecht in Saxe-Coburg; Bernhard in Saxe-Meiningen; Heinrich in Saxe-Römhild; Christian in Saxe-Eisenberg; Ernst in Saxe-Hildburghausen; Johann Ernst in Saxe-Saalfeld;
Duke of Saxe-Gotha
Reign	26 February 1640 – 26 March 1675
Predecessor	New creation
Duke of Saxe-Altenburg
Reign	14 April 1672 – 26 March 1675
Predecessor	Friedrich Wilhelm III
Born	25 December 1601; Altenburg, Duchy of Saxe-Weimar, Holy Roman Empire
Died	26 March 1675 (aged 73); Schloss Friedenstein, Gotha, Saxe-Gotha, Holy Roman Empire
Spouse	Elisabeth Sophie of Saxe-Altenburg (m. 1636)
Issue	Johann Ernest; Elisabeth Dorothea, Landgravine of Hesse-Darmstadt; Johann Ernest; Christian; Sophie; Johanna; Frederick I, Duke of Saxe-Gotha-Altenburg; Albert, Duke of Saxe-Coburg; Bernhard I, Duke of Saxe-Meiningen; Henry, Duke of Saxe-Römhild; Christian, Duke of Saxe-Eisenberg; Princess Dorothea Maria; Ernest, Duke of Saxe-Hildburghausen; Johann Philip; Johann Ernest IV, Duke of Saxe-Coburg-Saalfeld; Johanna Elisabeth; Johann Philip; Sophie Elisabeth;
House	House of Wettin
Father	Johann II, Duke of Saxe-Weimar
Mother	Dorothea Maria of Anhalt
Religion	Lutheran

Ernest I, called "Ernest the Pious" (25 December 1601 – 26 March 1675), was a duke of Saxe-Gotha and Saxe-Altenburg. The duchies were later merged into Saxe-Gotha-Altenburg.

He was the ninth but sixth surviving son of Johann II, Duke of Saxe-Weimar, and Dorothea Maria of Anhalt. His mother was a granddaughter of Christoph, Duke of Württemberg, and great-granddaughter of Ulrich, Duke of Württemberg.