John Muir was born in Maryhill, Scotland in 1879. After leaving school he became an engineer. He also joined the Independent Labour Party and began working closely with other socialists in Glasgow including John Wheatley, Emanuel Shinwell, James Maxton, David Kirkwood, Campbell Stephen, William Gallacher, Tom Johnston, Jimmie Stewart, Neil Maclean, George Hardie, George Buchanan and James Welsh.
Muir was opposed to Britain becoming involved in the First World War and was a member of Clyde Workers' Committee and organisation that had been formed to campaign against the Munitions Act, which forbade engineers from leaving the works where they were employed. Muir was also editor of the Clyde Workers' Committee journal, The Worker. In 1916 the newspaper was prosecuted under the Defence of the Realm Act for an article criticizing the war. Muir and William Gallacher were both found guilty and sent to prison. Gallacher for six months and Muir for a year.
In the 1922 General Election Muir was elected to the House of Commons for Maryhill. Also successful were several other militant socialists based in Glasgow including David Kirkwood, John Wheatley, Campbell Stephen, Emanuel Shinwell, James Maxton, Tom Johnston, Campbell Stephen, Jimmie Stewart, Neil Maclean, George Hardie, George Buchanan and James Welsh.
John Muir, who was Secretary of the Workers' Educational Association (1928-31), died on 10th January 1931.