The Main-d'œuvre immigrée was a French trade unionist organisation, composed of immigrant workers of the Confédération générale du travail unitaire (CGTU) in the 1920s. The MOI was affiliated to the Profintern. The MOI was initially named Main d'œuvre étrangère, but the French Communist Party, who in practice were in charge, changed the name from étrangère (foreign) to immigrée (immigrant) due to perceived xenophobia during the 1930s.

During the Second World War, Louis Grojnowski (called "Brunot") and Simon Cukier aka Alfred Grant took charge, and the organisation gave rise to an armed squad, the FTP-MOI, directed by Joseph Epstein.

After the mass arrest of more than 13,000 Jews in the Vel' d'Hiv Roundup in July 1942, the groups became somewhat more active. Pursued relentlessly by the Special Brigades of the Renseignements généraux, almost all the MOI fighters had been identified by the end of summer 1943. In the autumn the French police arrested them all, and nothing remained of the FTP-MOI.