This is a list of socialist, communist, and anarchist internationals.

Historic internationals

• Communist League, created in 1847 from the League of the Just.
• International Workingmen's Association (First International)
• Second International
• International Working Union of Socialist Parties (2½ International) 1921-1923
• Comintern (Third International), 1919-1943
• Fourth International, created in 1938 by Leon Trotsky.
• Labour and Socialist International 1923-1940

Existing internationals

• Socialist International founded in 1956
• International Federation of Anarchists (anarcho-communist)
• International Leninist Current (Leninist)
• International Workers Association (anarcho-syndicalist)
• World Socialist Movement (Marxist, anti-Leninist)

Lists of internationals

• List of left communist internationals
• List of Trotskyist internationals