The National Minority Movement was a British organisation, established in 1924 by the Communist Party of Great Britain, which attempted to organise a radical presence within the existing trade unions. The organization was headed by longtime unionist Tom Mann and future General Secretary of the CPGB Harry Pollitt.
The National Minority Movement was established at a convention held on 23–24 August 1924, attended by 271 delegates, claiming to represent 200,000 workers. By the time of the NMM's formation in 1924, the Comintern had abandoned strategies based on the prospect of an imminent world revolution, in favour of slow, gradual working within established institutions, including "pure and simple" reformist trade unions. The aim of the NMM was to convert the revolutionary minority of the working class into a majority. The NMM would organise workers who were dissatisfied with the existing unions but unwilling to join the Communist Party as well as those who were already party members. The Communists would thus increase their influence in workers without splitting the existing organisations.
The NMM was affiliated to the Red International of Labour Unions (RILU). Its president, from 1924 to 1929, was the veteran trade union activist Tom Mann and its General Secretary, over the same period, was Harry Pollitt. Other prominent figures included Wal Hannington, in charge of organization of the metal workers until transferred by the party to work organising the unemployed, the engineer J.T. "Jack" Murphy and coal miners A. J. Cook, Arthur Horner and Nat Watkins.
The Organising Secretary of the NMM was George Hardy, and George Fletcher served as Treasurer.