John McNair was a British socialist politician.
McNair was born in Boston, Lincolnshire, but moved to Tyneside at an early age. He left school when he was thirteen, working as an errand boy. He joined the Independent Labour Party, and was involved in Victor Grayson's election campaigns in 1910, on one occasion having to fill for an entire evening when Grayson failed to arrive. In 1911, he moved to Coventry, in an attempt to find regular employment, but his political activity made this difficult, and so, later in the year, he moved to Paris, where he lived and worked until 1923. He worked as the London Organising Secretary for the ILP during the 1924 general election, but felt that this had harmed his health, and he returned to Paris, where he worked for the next twelve years.
In 1936, McNair again returned to the UK, and was appointed as the ILP's national Organising Secretary and international representative. In this post, he travelled to Spain with John McGovern, in order to investigate the role of the Catholic Church in the Spanish Civil War.