Cécil Karl-August Timon Ernst Anton von Renthe-Fink (1885–1964) was a German diplomat.
He was plenipotentiary of Denmark from April 9, 1940 until 1942. In 1926 Renthe-Fink was posted to Dresden as Joint Secretary of the International Elbe Commission. This Commission had been set up by the League of Nations to ensure that the Elbe was kept as a free outlet to the North Sea for shipping from Czechoslovakia.
He was appointed ambassador to Denmark in 1936. In 1939 he became a member of the Nazi party. After the occupation of Denmark he became plenipotentiary. In 1942 he was replaced by Dr. Werner Best after the Telegram Crisis. Berlin was hoping for a harder line.
In 1943 Renthe-Fink was posted to Vichy France. In 1943, the German ministers Joachim von Ribbentrop and Renthe-Fink proposed the creation of a European confederacy, which would have had a single currency, a central bank in Berlin, a regional principle, a labour policy and economic and trading agreements. He was married to Christa von Eckstadt, daughter of Graf Vitzthum von Eckstadt.