Ribbentrop, Joachim von (1893–1946), a German Nazi diplomat. Ribbentrop was ambassador to Great Britain, 1936–38, and foreign minister, 1938–45. He negotiated the Soviet-German pact of 1939 and brought Japan into the German-Italian alliance in 1940. He also helped work out details of the annexation of Austria, the partition of Czechoslovakia, and the invasions of other European countries.

Ribbentrop was born in Wesel, Germany. He was a cavalry officer in World War I and became a champagne salesman after the war. He joined the Nazi party in 1932. Ribbentrop was found guilty of war crimes at the Nuremberg Trials and was hanged.