Argentina, Australia, Belgium, Bolivia, Brazil (withdrew 14 June 1926), Canada, Chile (withdrew 14 May 1938), China, Colombia, Cuba, Czechoslovakia (membership dissolved 15 March 1939), Denmark (withdrew in July 1940), El Salvador (withdrew 11 August 1937), France, Greece, Guatemala (withdrew 26 May 1936), Haiti (withdrew in April 1942), Honduras (withdrew 10 July 1936), India, Italy (withdrew 11 December 1937), Japan (withdrew 27 March 1933), Liberia, Netherlands, New Zealand, Nicaragua (withdrew 27 June 1936), Norway, Panama, Paraguay (withdrew 23 February 1935), Persia (since 1934 - Iran), Peru (withdrew in April 1939), Poland, Portugal, Rumania (withdrew in July 1940), Kingdom of Serbs, Croats and Slovenes (since 1929 - Yugoslavia), Siam (since 1939 - Thailand), South Africa, Spain (withdrew in May 1939), Sweden, Switzerland, United Kingdom, Uruguay, Venezuela (withdrew 12 July 1938)
Ecuador, Hejaz and the United States were orignal signatory members of the League Covenant 28 June 1919, but did not ratify covenant

Estonia (membership dissolved 6 August 1940), Latvia (membership dissolved 5 August 1940), Lithuania (membership dissolved 3 August 1940)