The Plebs' League was a British educational and political organisation which originated around a Marxist way of thinking in 1908 and was active until 1926.
Central to the formation of the League was Noah Ablett, a miner from the Rhondda who was at the core of a group at Ruskin College, Oxford who challenged the lecturers' opposition to Marxism. In the 1907–8 academic year, Ablett began leading unofficial classes in Marxist political economy which were attended by Ebby Edwards, among others. Ablett returned to South Wales in 1908, where he began promoting Marxist education through local branches of the Independent Labour Party.
A mixture of students and former students at Ruskin founded the Plebs' League in November 1908, also launching the Plebs' Magazine. In the first issue of the Plebs, dated February 1909, Ablett contributed an article on the need for independent working class education. The League ran classes teaching Marxist principles and later syndicalist ideas.
During 1909, student agitation for Marxism continued at Ruskin. The students were supported by the Principal, Dennis Hird, and when he was dismissed the students went on strike, refusing to attend classes. The rebels formed the Central Labour College, which worked closely with the Plebs' League.
By 1910, the Plebs' League was active in South Wales, Lancashire and Scotland. Activists included A. J. Cook, William Mainwaring, Mark Starr and John Maclean.
The League had sympathies with De Leonism, primarily represented in Britain by the Socialist Labour Party. It later had a relationship with the Communist Party of Great Britain.
The League was absorbed by the National Council of Labour Colleges the year after the 1926 United Kingdom general strike, although the Plebs' Magazine continued to appear for many years.