Duke Ernst I of Saxe-Coburg-Saalfeld (1784-1844) was a German nobleman and the first Duke of the duchy of Saxe-Coburg-Saalfeld. He ruled from 1826 until his death in 1844, overseeing a period of modernization and development in his territory. Ernst I was known for his interest in culture and the arts, which contributed to the duchy's reputation during his reign. Ernst I was also a member of the House of Saxe-Coburg, a prominent family in European royalty. His descendants, including Prince Albert, the husband of Queen Victoria, played significant roles in various European royal families, further intertwining the history of the duchy with broader European affairs.