John Scott Maclay, 1st Viscount Muirshiel, (26 October 1905 – 17 August 1992) was a British politician, sitting as a National Liberal and Conservative Member of Parliament before the party was fully assimilated into the Unionist Party in Scotland in the mid 1960s.Lord Muirshiel served as Secretary of State for Scotland from 1957 to 1962 within Harold Macmillan's Conservative government, having held a number of junior ministerial posts beforehand.