Princess Konstancja Czartoryska (c. 1696 or 29 January 1700 – 27 October 1759) was a Polish-Lithuanian noblewoman and the mother of King Stanisław II August of Poland.

[1] The marriage was arranged by the assistance of Jakub Henryk Flemming as an alliance between the Poniatowski and Czartoryski family.

Konstancja Czartoryska came to acquire a great influence within the family and was described as a driving force behind the political career of her spouse and her brothers.

In January 1736, she visited Koszalin and successfully persuaded Michał Czartoryski to support August III as king.

In 1743, she was involved in the scandal when her son was Kazimierz challenged to a duel by Adam Tarła after having danced with Tarla's wife.