The International Socialists is a Canadian Trotskyist group. It is part of the International Socialist Tendency, of which the British Socialist Workers Party (SWP) is the most prominent group. The IS publishes an English-language fortnightly paper, Socialist Worker, a French-language monthly, Résistance!, and an annual theoretical journal Marxism.

The International Socialists (Danish: Internationale Socialister) is a Trotskyist organisation in Denmark.

The International Socialists (Norwegian: Internasjonale Sosialister) is a Trotskyist organisation in Norway founded in the early 1980s. It is part of the International Socialist Tendency led by the British Socialist Workers Party.

International Socialists (Dutch: Internationale Socialisten) is a revolutionary, Trotskyist organisation in the Netherlands. It is part of the International Socialist Tendency led by the British Socialist Workers Party.

The International Socialists were a Trotskyist group in the United States. They were founded as the Independent Socialist Club in 1964 in Berkeley, California by a group of former Independent Socialist League members around Hal Draper, who had opposed its dissolution into the Socialist Party of America in 1958.

The International Socialists is the Scottish platform of the Committee for a Workers International in the Scottish Socialist Party. The group is descended from the Scottish Militant Labour which formed the Scottish Socialist Alliance in 1996 after a debate amongst CWI members in Scotland on what sort of organization to form. The SSA was launced as a broad left formation that itself was not affiliated with the CWI but withinn which Scottish Militant Labour, renamed the International Socialist Movement took a leading role.