| Archduke Ferdinand Karl Viktor | |
| Issue: | Maria Theresa, Queen of Bavaria |
| House: | Austria-Este |
| Father: | Francis IV of Modena |
| Mother: | Maria Beatrice of Savoy |
| Religion: | Roman Catholicism |
| Birth Date: | 20 July 1821 |
| Birth Place: | Modena, Duchy of Modena and Reggio |
| Death Place: | Brno, Margraviate of Moravia, Austrian Empire |
Ferdinand Karl Viktor (20 July 1821 – 15 December 1849) was Archduke of Austria-Este and Prince of Modena.
Born in Modena, he was the second son of Francis IV of Modena and his niece and wife, Maria Beatrice of Savoy. His paternal grandmother had been heiress to the Duchy of Modena, because her father Ercole III d'Este had no sons.
Ferdinand married Archduchess Elisabeth Franziska of Austria, daughter of Archduke Josef Anton of Austria and his third wife Duchess Maria Dorothea of Württemberg on 4 December 1846 in the Schönbrunn Palace in Vienna. Elisabeth and Ferdinand had one daughter:
Ferdinand, who was a Feldmarschalleutnant (Austrian "two stars" general rank), died at Brno a few months later at the age of 28 from typhus. His widow remarried with Archduke Karl Ferdinand of Austria.
Ferdinand is the link in the Jacobite succession between his brother Francis V, Duke of Modena and his daughter Maria Theresa of Austria-Este.