John Ramsay Bryce Muir (30 September 1872 – 4 May 1941) was a British historian, Liberal Party politician and thinker who made a significant contribution to the development of liberal political philosophy in the 1920s and 1930s through his work on domestic industrial policy and his promotion of the international policy of interdependency.

[1] Muir was born at Otterburn, Northumberland, the oldest of five children of a Reformed Presbyterian minister.

Muir was also a prominent Liberal writer contributing frequently to The Nation and the Weekly Westminster.

He stood for Parliament again at five further elections, without success: Muir was also a leading figure in the National Liberal Federation (NLF), being its chairman from 1931 to 1933 and president from 1933 to 1933.

Although Muir was associated closely with the progressive ideas coming out of the Liberal Summer Schools, the radical solutions for unemployment, industrial and social reform which were inspired by Maynard Keynes, Lloyd George and William Beveridge, he was also something of a classical Liberal too.