| Magdalene Sibylle of Saxe-Weissenfels | |
| Consort: | yes |
| Succession: | Duchess consort of Saxe-Eisenach |
| Reign: | 28 July 1708 – 28 November 1726 |
| House: | House of Wettin |
| Father: | Johann Adolf I, Duke of Saxe-Weissenfels |
| Mother: | Johanna Magdalena of Saxe-Altenburg |
| Spouse: | John William III, Duke of Saxe-Eisenach |
| Issue: | Christiane Wilhelmine, Princess of Nassau-Usingen |
| Birth Date: | 3 September 1673 |
| Birth Place: | Halle |
| Death Place: | Eisenach |
Magdalene Sibylle of Saxe-Weissenfels (3 September 1673 – 28 November 1726), was a German noblewoman member of the House of Wettin (Albertine line) and by marriage Duchess of Saxe-Eisenach.
Born in Halle, she was the oldest daughter and first child of Duke Johann Adolf I of Saxe-Weissenfels and his wife Johanna Magdalena, the daughter of Duke Frederick William II of Saxe-Altenburg. She was named after her paternal great-grandmother, Duchess Magdalene Sibylle of Prussia.
In Weissenfels on 28 July 1708, Magdalene Sibylle married John William III, Duke of Saxe-Eisenach as his third wife. They had three children, of whom only one survived to adulthood:
She died in Eisenach aged 53 and was buried in the Georgenkirche, Eisenach.[1]