The Industrial Workers of Great Britain was a group which promoted industrial unionism in the early 20th century.
The Industrial Workers of the World (IWW) was founded in Chicago in 1905. It called for industrial unionism and aimed to organise workers in all industries, and many of its activists were members of the Socialist Labor Party of America. The British Socialist Labour Party had been founded in 1903 by Scottish supporters of Daniel de Leon, a leading figure in the American SLP and the IWW. In 1906, the British party formally adopted a policy of industrial unionism.
In 1906, the British SLP founded the British Advocates of Industrial Unionism (BAIU), a small propaganda organisation which called for the formation of revolutionary unions in the pattern of the IWW. The group was officially launched in August 1907, with Tom Bell as its Secretary.
In 1908, the IWW split into Chicago- and Detroit-based organisations. In Britain, E. J. B. Allen and his supporters mirrored the Chicago section's call for the cessation of political activity which was not channelled through trade unions. They founded the Industrialist League and developed links with the Chicago-based IWW.
The BAIU was refounded as the "Industrial Workers of Great Britain" (IWGB) in 1909. The group also changed tactics: instead of campaigning for trade unions to voluntarily dissolve themselves into a new industrial union, it aimed to recruit workers directly into local groups of the organisation until it had sufficient numbers to form genuine industrial unions. Even before the name change, the group had received some support in three large factories: Singer's Sewing Machine Company in Clydebank, the Argyll Motor Works in Alexandria and the Albion Motor Works in Scotstoun, all near Glasgow. By the end of the decade, the group claimed a membership of 4,000 at Singer's alone.