Clemens Erwein Heinrich Karl Bonaventura Freiherr von und zu Franckenstein (14 July 1875 – 19 August 1942) was a German opera composer, studying in Vienna, Austria, and later in Munich, Germany, with
Ludwig Thuille and at the Hoch Conservatory in Frankfurt with
Iwan Knorr. After a visit to the USA he conducted the Moody-Manners Opera Company, acted from 1902–1907 as opera conductor in London, then worked at the court theatres of Wiesbaden and Berlin, until the court theaters were abolished after the First World War. He was the last royal general director of the Bayerische Staatsoper in Munich (1912–1918 and 1924–1934) and the only one who exercised this office twice. He produced the Munich Opera Festival through 1934 when he was forced out by Nazi prohibitions.
Franckenstein was born in Wiesentheid, Germany to Karl Freiherr von und zu Franckenstein (1831–1898) and Elma Gräfin von Schönborn-Wiesentheid (1841–1884). His brother was Austrian Ambassador to England, Georg von und zu Franckenstein (1878–1953). Georg's son, actor Clement von Franckenstein (1944–2019), was his nephew.
Franckenstein died in Hechendorf am Pilsensee, Oberbayern, Germany at age 67.
