Marie Elisabeth of Brunswick-Wolfenbüttel (7 January 1638 - 15 February 1687), was a German noblewoman member of the House of Welf and by her two marriages Duchess of Saxe-Eisenach and Saxe-Coburg. Born in Brunswick, she was the second of the three children of Augustus the Younger, Duke of Brunswick-Lüneburg and his third wife, Duchess Elisabeth Sophie of Mecklenburg. Marie Elisabeth and her older brother Ferdinand Albert are the only surviving children of their parents' marriage. In addition, they had seven older half-siblings from Duke Augustus' two previous marriages, of whom only four survive adulthood: Rudolph Augustus, Sibylle Ursula (by marriage Duchess of Holstein-Glücksburg), Clara Augusta (by marriage Duchess of Württemberg-Neustadt) and Anthony Ulrich, all born from Augustus' se