Tadao Yanaihara (矢内原 忠雄 Yanaihara Tadao, January 27, 1893 – December 25, 1961) was a Japanese economist, educator and Christian pacifist. The first director of Shakai Kagaku Kenkyűjo (Institute of Social Science or Shaken) at the University of Tokyo, studied at Toynbee Hall and School of Economics and Political Science (London School of Economics).
Born in Ehime Prefecture, Yanaihara became a Christian under the influence of Uchimura Kanzō’s Mukyokai or Nonchurch Movement, while he was studying at the University of Tokyo. In the 1930s he was appointed to the chair of colonial studies at the University of Tokyo, formerly held by his teacher Nitobe Inazō. However, Yanaihara’s pacifist views and emphasis on indigenous self-determination, which he partly inherited from Nitobe – a Quaker and founding member of the League of Nations – came into a full conflict with Japan’s wartime government during the World War II. He was noted for his criticism of Japan’s expansionist policies. As a result, Yanaihara was forced to resign from teaching under pressure by right-wing scholars in 1937. Yanaihara resumed his teaching after the war and taught international economics at the University of Tokyo. He served as the president of the University from 1951 to 1957.