John Lincoln Mahon

John Lincoln Mahon (8 June 1865 – 19 November 1933) was a Scottish trade unionist and politician, best known as a prominent socialist activist.

Mahon was born in Edinburgh, to Irish parents, with the surname "McMahon". He followed in his father's trade by becoming an engine fitter.

Mahon was an early member of the Social Democratic Federation (SDF), in June 1884 launching "The Social Reform Publishing Company", a venture that did not last more than a few months, but also leading socialist propaganda in Edinburgh. However, instead of forming an Edinburgh branch of the SDF, they formed the Scottish Land and Labour League which affiliated to the SDF. Mahon sided with William Morris when he seceded with a majority of the SDF executive to form the Socialist League.

In 1884, Mahon moved to London, where he served as the first secretary of the Socialist League. However, he stood down in 1885, and in 1887 and early 1888 he travelled the north of England. With Henry Alfred Barker, he founded the Labour Union, which adopted the programme as its platform, and he served as joint chair of the party until August 1889.

Mahon moved to Leeds in 1890, but found himself blacklisted from most jobs due to his political activism. His son, John, was born in 1901, like his father was politically active and became a Communist, standing for election unsuccessfully in the 1949 St Pancras North by-election.

Mahon returned to London in 1904, remaining there for the remainder of his life,