Sir John Miller Martin KCMG CB CVO (15 October 1904 – 31 March 1991) was a British civil servant who served as Principal Private Secretary to the Prime Minister, Winston Churchill, during World War II.

He was educated at the Edinburgh Academy and won a scholarship to Corpus Christi College, Oxford.

[1] Having passed the civil service examination in 1927 he joined the Colonial and Dominion offices.

After a long and distinguished career his final posting was British High Commissioner for Malta in 1965 before retirement in 1967.

This article about a person involved in governance in the United Kingdom or its predecessor states is a stub.