William, Duke of Saxe-Weimar
| Wilhelm | |
|---|---|
| Duke of Saxe-Weimar and Jena | |
| Reign | 1620–1662 |
| Predecessor | Johann Ernst I |
| Successor | Johann Ernst II in Saxe-Weimar Bernhard II in Saxe-Jena |
| Ruler of Saxe-Eisenach | |
| Reign | 1644–1662 |
| Predecessor | Albrecht |
| Successor | Adolf Wilhelm in Saxe-Eisenach Johann Georg in Saxe-Marksuhl |
| Born | 11 April 1598 Altenburg |
| Died | 17 May 1662 (aged 64) Weimar |
| Spouse | |
| Issue | Prince Wilhelm, Hereditary Duke of Saxe-Weimar and Jena Johann Ernst II, Duke of Saxe-Weimar Prince Johann Wilhelm Adolf Wilhelm, Duke of Saxe-Eisenach Johann Georg I, Duke of Saxe-Marksuhl Princess Wilhelmine Eleonore Bernhard II, Duke of Saxe-Jena Prince Frederick Dorothea Marie, Duchess of Saxe-Zeitz |
| House | House of Wettin |
| Father | Johann, Duke of Saxe-Weimar |
| Mother | Dorothea Maria of Anhalt |
| Religion | Lutheran |
Wilhelm, Duke of Saxe-Weimar (Altenburg, 11 April 1598 – Weimar, 17 May 1662), was a duke of Saxe-Weimar.
Wilhelm was the fifth (but third surviving) son of Johann, Duke of Saxe-Weimar, and Dorothea Maria of Anhalt. He was brother to Bernard of Saxe-Weimar, a successful Protestant general in the Thirty Years' War, and to Ernest I, Duke of Saxe-Gotha (later Altenburg), a successful and well-regarded ruler known as "The Pious".