former industrial union in the United States and Canada that represented workers in the women's clothing industry. When the ILGWU was formed in 1900, most of its members were Jewish immigrants employed in sweatshops—i.e., small manufacturing establishments that employed workers under unfair and unsanitary conditions. Successful strikes in 1909 and 1910 in New York City by the ILGWU resulted in a “protocol of peace” between the women's clothing industry and labour. The protocol greatly improved conditions for the garment-makers; wages were increased, working hours were reduced, the union was recognized by the clothing manufacturers, and a board of arbitration was established to handle labour-management disputes. David Dubinsky (Dubinsky, David), who later served as the union's president from 1932 to 1966, led a successful battle against a communist attempt to gain control of the ILGWU in the 1920s. When resolutions that would have allowed craft unions to organize the workers in mass-production industries were defeated at the convention of the American Federation of Labor (AFL) in 1935, the ILGWU and seven other AFL unions formed the Committee for Industrial Organization (CIO). All eight were expelled from the AFL in 1937. When the CIO became the Congress of Industrial Organizations in 1938, the ILGWU withdrew and two years later returned to the AFL.

Under Dubinsky's leadership the union grew from 45,000 members in 1932 to 450,000 in the 1960s. He transformed the ILGWU from a faction-ridden, insolvent regional union into a strong and progressive international organization that succeeded in improving the pay and working conditions of its members. The union was also a founder of the Liberal Party in New York state.

From the 1970s the ILGWU's membership shrank as firms in the United States shifted much of their apparel production to Asia and Latin America to take advantage of lower labour costs. In 1995 the ILGWU merged with the Amalgamated Clothing and Textile Workers' Union to form a new union, the Union of Needletrades, Industrial (Needletrades, Industrial and Textile Employees, Union of) and Textile Employees.