Ernest I, Duke of Saxe-Gotha (1601-1675), was a German nobleman and a member of the House of Wettin. He ruled the duchy of Saxe-Gotha from 1640 until his death, overseeing a period of relative peace and stability following the Thirty Years' War. His reign is noted for promoting education and the arts, as well as for his efforts in the administration of the duchy. Ernest I was instrumental in the establishment of the University of Jena and supported the development of various cultural institutions. He was also known for his diplomatic skills, maintaining good relations with neighboring territories and contributing to the political landscape of Thuringia.