International Socialists
- Committee for a Workers' International (1974)
- International Socialist Alternative
- International Socialist Alternative (Austria)
- International Socialist Circle
- International Socialist Group
- International Socialist Group (disambiguation)
- International Socialist League
- International Socialist Left
- International Socialist Movement (South Africa)
- International Socialist Network
- International Socialist Opposition
- International Socialist Organization
- International Socialist Organization (disambiguation)
- International Socialist Party
- International Socialist Party of Subcarpathian Rus'
- International Socialists (Australia)
- International Socialists (Canada)
- International Socialists (Denmark)
- International Socialists (Ireland)
- International Socialists (Netherlands)
- International Socialists (Norway)
- International Socialists (Scotland)
- International Socialists (Sweden)
- International Socialists (UK)
- International Socialists (United States)
- International Socialists of Germany
- International socialism
- List of left-wing internationals