| Konstancja Sanguszko | |
| Nationality: | Polish |
| Known For: | political role during the Bar Confederation (1768–1772) |
| Spouse: | Janusz Aleksander Sanguszko (m. 1731) |
| Mother: | Joanna Catherine Denhoff |
| Father: | Stanisław Ernest Denhoff |
Princess Konstancja Sanguszko (1716–1791), was a Polish magnate.
She was the daughter of Count Stanislas Ernst von Dönhoff and Countess Maria Katharina Johanna von Dönhoff (1686-1723). Konstancja was married to Prince Janusz Aleksander Sanguszko in 1731. She lived separated from her spouse, who was homosexual and abandoned her shortly after the wedding. She lived in Gdansk, and played a political role during the Bar Confederation (1768–1772), when she contributed to the formation of the Confederation. In 1780, she remarried Józef Rogaliński, who abandoned her, wasted her fortune and left her to die in poverty. She was involved in long lawsuits with both of her husbands which attracted great attention.