Neosocialism was a political faction that existed in France and Belgium during the 1930s and which included several revisionist tendencies in the French Section of the Workers' International (SFIO).
During the 1930s, the faction gradually distanced itself from revolutionary Marxism and reformist socialism while stopping short of merging into the traditional class-collaborative movement represented by the Radical Party. Instead, they advocated a revolution from above, which they termed as a constructive revolution. In France, this brought them into conflict with the Socialist Party's traditional policy of anti-governmentalism and the neosocialists were expelled from SFIO.