He was born in Warsaw as the son of the then royal courtier Teodor Denhoff and Katarzyna Franciszka von Bessen,[3] mistress of king John II Casimir Vasa.

In the days of John III Sobieski, Denhoff represented Polish interests in the Holy See in the Vatican.

[4] Denhoff held various positions in the Roman Curia, including the Supreme Court of the Apostolic Signatura.

Pope Innocent XI created him Cardinal at the Consistory of 2 September 1686 and was appointed bishop of Cesena in 1687.

Shortly before his death in 1697 he resigned from the Diocese of Cesena and died in Rome.