Duke Ernst I of Saxe-Gotha (1601-1675) was a German nobleman and a member of the House of Saxe-Gotha. He ruled the duchy of Saxe-Gotha from 1640 until his death, overseeing a period of relative stability and development following the Thirty Years' War. Ernst I was known for his efforts to promote education and the arts within his territory. Under his leadership, the duchy became a center for culture and learning, attracting scholars and artists. He also played a significant role in the political landscape of Thuringia, working to strengthen the influence of his duchy among the surrounding territories.