| Nicholas of Saint-Omer | |
|---|---|
| Lord of one half of Thebes | |
| Tenure | Before 1299 – 1311 |
| Predecessor | Otho of Saint-Omer |
| Successor | Catalan conquest |
| Lord of one third of Akova | |
| Tenure | Before 1290 – 1314 |
| Predecessor | John of Saint-Omer |
| Marshal of Achaea | |
| Tenure | Before 1290 – 1314 |
| Predecessor | John of Saint-Omer |
| Died | 30 January 1314 |
| Spouse | Guglielma Orsini |
| Dynasty | Saint-Omer |
| Father | John of Saint-Omer |
| Mother | Margaret of Passavant |
| Religion | Roman Catholic |
Nicholas III of Saint-Omer (died 30 January 1314) was one of the most powerful and influential lords of Frankish Greece. He was hereditary Marshal of the Principality of Achaea, lord of one third of Akova and of one half of Thebes. He also served on three occasions as bailli of the Principality of Achaea (1300–1302, 1304–1307, c. 1311–1314).