Belgian statesman who, as Belgium's representative to the Paris Peace Conference after World War I, helped draft the covenant of the League of Nations.

While teaching parliamentary history at the Free University of Brussels (1898–1914), Hymans entered the Chamber of Deputies (1900) and soon became a leader of the Liberal Party. He served as minister to Great Britain from 1915 to 1917 and as minister of economic affairs (1917). As minister for foreign affairs (1918–20), he represented Belgium at the peace conference (1919–20) and served as president of the League of Nations' first assembly (1920) in Geneva.

After helping to form the customs union of Belgium and Luxembourg in 1921, Hymans played a leading part in negotiating the Dawes Plan (1924), which enabled Germany to resume reparations payments to the Allies. He then held a series of government posts: minister of justice (1926–27), minister for foreign affairs (1927–35), and member of the council of ministers (1935–36). His Pages libérales (“Liberal Notes”) was published in 1936.