Leopold Ružicka (Croatian pronunciation: [ru?it?ka]; 13 September 1887 – 26 September 1976) was a Croatian-Swiss scientist and joint winner of the 1939 Nobel Prize in Chemistry who worked most of his life in Switzerland.
He received eight honoris causa doctorates in science, medicine, and law; seven prizes and medals; and twenty-four honorary memberships in chemical, biochemical, and other scientific societies.