| Native Name: | Herzogtum Sachsen-Marksuhl |
| Conventional Long Name: | Duchy of Saxe-Marksuhl |
| Common Name: | Saxe-Marksuhl |
| Era: | Middle Ages |
| Status: | Vassal |
| Empire: | Holy Roman Empire |
| Government Type: | Principality |
| Year Start: | 1662 |
| Year End: | 1671 |
| Event Start: | Partitioned from Saxe-Weimar |
| Date Start: | 1662 |
| Event End: | Incorporated into Saxe-Eisenach |
| Date End: | 1671 |
| P1: | Saxe-Weimar |
| S1: | Saxe-Eisenach |
| Capital: | Marksuhl |
The Duchy of Saxe-Marksuhl was one of the Saxon Duchies held by the Ernestine line of the Wettin Dynasty. Established in 1662 for John George I, third son of Wilhelm, Duke of Saxe-Weimar. Originally John George was supposed to share Saxe-Eisenach with his older brother, Adolf William.[1] Johann Georg finally accepted the receipt of an income from the duchy of Saxe-Eisenach and made his residence in the small town of Marksuhl. Saxe-Marksuhl was reincorporated into Saxe-Eisenach on the accession of John George to the Duchy of Saxe-Eisenach upon his nephew's death in 1671.