Risto Heikki Ryti (Finnish pronunciation: [ˈristo ˈhei̯kːi ˈryti]; 3 February 1889 – 25 October 1956) was a Finnish politician who served as the president of Finland from 1940 to 1944. Ryti started his career as a politician in the field of economics and as a political background figure during the interwar period. He made a wide range of international contacts in the world of banking and within the framework of the League of Nations. Ryti served as prime minister during the Winter War and the Interim Peace, and as president during the Continuation War.
Ryti penned the 1944 Ryti–Ribbentrop Agreement – named after himself and Joachim von Ribbentrop – a personal letter to Nazi German Führer Adolf Hitler whereby Ryti agreed not to reach a separate peace in the Continuation War against the Soviet Union without approval from Nazi Germany, in order to secure German military aid for Finland to stop the Soviet Vyborg–Petrozavodsk Offensive against Finland. His resignation soon afterwards allowed his successor, Carl Gustaf Emil Mannerheim, to bypass the agreement and make peace with the Soviet Union once the offensive had been stopped.