Aloys Wenzel, Prince von Kaunitz-Rietberg (19 June 1774 - 15 November 1848) was a German nobleman and a diplomat of the Austrian Empire.
From the Kaunitz-Rietberg-Questenberg branch of his family, he was the last count of Rietberg, since the county was retained by the Kingdom of Westphalia after the Congress of Vienna.
His sister Maria Eleonore (1775-1825) was the first wife of Klemens von Metternich.
Born in Vienna, he died in Paris.
He served as a diplomat in Dresden, Copenhagen (1801-1804), Naples (1805-1807), Madrid (1815-1817) and the Holy See (1817-1820).