Dame Sarah MacIntosh DCMG (born 7 August 1969[citation needed]) is a British diplomat who is the Deputy National Security Adviser for International Affairs.

MacIntosh joined the Foreign and Commonwealth Office (FCO) in 1991 and served at the UK missions to the UN in New York and Vienna, and in the British embassy in Madrid.

She was strategy coordinator for the UN mission in Kosovo 2004–05, and High Commissioner to Sierra Leone (and non-resident Ambassador to Liberia) 2006–08.

She then took a fellowship at the Weatherhead Center for International Affairs at Harvard University 2008–09.

[1] In November 2016 the FCO announced that she had been appointed Permanent Representative to the United Kingdom's Delegation to NATO.