John Blackwood (2 October 1696 – 12 November 1777) was a Scottish merchant who early in his life was a slave trader in New Spain and a politician who sat in the House of Commons briefly from 1727 to 1728. Later he became a noted and sought-after art dealer. He was based in London but travelled widely on the Continent, and was one of the first dealers to introduce the works of Murillo to Britain.