| Karl of Austria-Este | |
| Prince Archbishop of Esztergom | |
| Full Name: | Karl Ambrosius Joseph Johann Baptist |
| House: | House of Austria-Este |
| Father: | Archduke Ferdinand of Austria-Este |
| Mother: | Maria Beatrice Ricciarda d'Este |
| Birth Date: | 2 November 1785 |
| Birth Place: | Milan, Duchy of Milan |
| Death Date: | (aged 23) |
Archduke Karl Ambrosius Joseph Johann Baptist of Austria-Este (Hungarian: '''Habsburg–Estei Károly Ambrus főherceg'''; Milan, 2 November 1785 – Tata, Hungary 2 September 1809) was an Archbishop of Esztergom.
Born His Royal Highness Archduke Karl Ambrosius of Austria-Este, the sixth son of Archduke Ferdinand of Austria-Este (son of Maria Theresa of Austria and governor of the Duchy of Milan) and of his wife, Princess Maria Beatrice Ricciarda d'Este, Duchess of Massa and Princess of Carrara, Lady of Lunigiana.
He spent his youth in Monza, where his family had fled after the French invasion of the Duchy of Modena. After staying in Verona, Padua, Trieste and Laibach, his family moved in Wiener Neustadt.
Because of his fragility, he was intended for church life. He became Bishop of Vác in 1806 and Archbishop of Esztergom, two years later, making him Primate of Hungary.
He died one year later at the age of 23.