Ambrose Barker (20 April 1859 – 14 February 1953) was a British anarchist activist. Born in Earls Barton, Northamptonshire, Barker moved to Leyton in London in 1878 to become an assistant schoolmaster and joined the National Secular Society. In 1880, he openly opposed Charles Bradlaugh's support for the Coercion Bill. Bradlaugh was a leading figure in the Secular Society. Barker gained the support of the majority of the Stratford branch of the Secular Society, but failed to influence its national politics.