The Fourth International may refer to:
Original The Communist Workers' International, or Fourth Communist International, of left communists (1922–1933) The Fourth International, the World Party of Socialist Revolution, founded by Trotskyists in 1938 Fourth International (post-reunification), successor organisation to Fourth International, founded 1963
Successor / splinter groups The International Committee of the Fourth International, a group which claimed the political heritage of the Fourth International, founded 1953 The Fourth International Posadist, group which claimed the political heritage of the Fourth International founded in 1962 by J. Posadas in Argentina
See also List of Trotskyist internationals