James MacDonald (1857 - 21 May 1938) was a British trade unionist. Born in Edinburgh, MacDonald trained as a tailor and moved to London in 1881. He joined the and the Manhood Suffrage League, but it was reading Friedrich Engels' articles in the that convinced him of socialism. As a result, he joined the Social Democratic Federation (SDF), but left in 1885 to join the Socialist Union. However, he rejoined the SDF in 1887. In 1905, he left the Amalgamated Society of Tailors to found the . He later retired to Australia, but returned to the UK a few years before his death.