Polish statesman who made his family party of Czartoryskis, the so-called Familia (Czartoryski family), the leading party in Poland.

Educated at Paris, Florence, and Rome, Czartoryski attached himself to the Saxon court and obtained the vice chancellorship of Lithuania. He was one of the nobles who, on the illness of King Augustus II of Poland in 1727, signed the secret guarantee of the Polish succession to that king's son; but he supported Stanisław Leszczyński when the latter was placed upon the throne by the influence of France in 1733. When Stanisław abdicated in 1735, Czartoryski voted for Augustus III, who employed him and his family against a rival family, the Potockis. Under him and his brother August, the Familia became the leading party, and promising young men were educated by them at the family palace at Puławy. Czartoryski concerned himself with internal political reform rather than diplomatic schemes. He aimed at the restoration of the royal prerogative and the abolition of the liberum veto.

Czartoryski reached the height of his power in 1752, when he was entrusted with the great seal of Lithuania; but, when his rival, Jerzy Mniszek, began to prevail at Dresden, he sought a reconciliation with his opponents at home and foreign support in England and Russia. His attempt to secure reforms with the help of Russia failed. After 1767 he retired to his estates, whence he saw the first partition of Poland; but he left a legacy of his ideas to his nephew King Stanisław II Poniatowski (Stanisław II August Poniatowski) and to his other nephew Adam Kasimierz Czartoryski (Czartoryski, Adam Kazimierz, Prince), who became the father of Adam Jerzy Czartoryski (Czartoryski, Adam Jerzy, Prince) (qq.v.).