Augustyn Michaà  Stefan Radziejowski (3 December 1645 â 13 October 1705) was a Polish religious leader who was archbishop of Gniezno, bishop of Warmia, and cardinal primate of the Catholic Church in Poland. He was the son of Hieronim Radziejowski. After the death of the Polish king John III Sobieski, with whom he had a very good relationship, he functioned as the Interrex until the choice of a new king.
Radziejowski first supported the candidacy of François Louis, Prince of Conti. Later, he supported August II the Strong, the eventual successor to John III. Radziejowski is noted as an art patron.
He died in Gdaà Âsk (Danzig) on 13 October 1705.