Augustyn Michał Stefan Radziejowski (3 December 1645 – 13 October 1705) was an archbishop of Gniezno, bishop of Warmia, and cardinal primate of the Roman Catholic Church in Poland,[1] son of Hieronim Radziejowski.

After the death of the Polish king John III Sobieski, with whom he had a very good relationship,[2] he functioned as 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.

This article about a Polish Catholic bishop or archbishop is a stub.