William Emmanuel Rappard (April 22, 1883, New York City – April 29, 1958) was an influential academic and diplomat of the interwar-period, a passionate defender of the international scene.
One of Rappard's greatest achievements was as a co-founder of the Graduate Institute of International Studies (now IHEID), Professor of Economic History at the University of Geneva, Rector of the University of Geneva in 1926, Director of the Mandate Section of the League of Nations Secretariat (and as a member of the Permanent Mandates Commission for all 18 years of its active life), and Swiss Representative at the International Labour Organization (ILO), as well as at the United Nations Organization (UN) and at the United States Embassy.