Isaac Brassington (1870 – 13 December 1932) was a British trade unionist and political activist. Born in Sutton on the Hill in Derbyshire, Brassington began working on the railways, and joined the General Railway Workers' Union (GRWU). By 1906, he was based in Leeds and active in the Independent Labour Party (ILP). He was elected to Leeds City Council in 1907, representing East Hunslet. In 1908, he became editor of the GRWU's journal, Railway Worker, then in 1911 he became an organiser for the GRWU. The union became part of the National Union of Railwaymen, and Brassington became its organiser for the Lancashire area, moving to Manchester.