Sir Alexander Knox Helm GBE KCMG (23 March 1893 – 7 March 1964) was a British diplomat who served as ambassador to Turkey and was the last Governor-General of the Sudan.
Born to W.H. Helm of Dumfries, Alexander Knox Helm was educated at Dumfries Academy and King's College, Cambridge.
In 1912 he passed the examination for what were then called second division clerkships and was appointed to the Foreign Office. He served as a member of the East Registry. A keen volunteer when World War I broke out, he was allowed by the Foreign Office to join his field artillery unit, being promoted second lieutenant in 1917 and serving in that capacity in Palestine. As a humble clerk, he had performed only routine duties but distinguished himself through his assiduity and retentive memory.
Thus, when the war ended he was selected under the special recruitment scheme for filling vacancies caused by the war and appointed to the Levant Consular Service. After a short period of training in Oriental languages at King's College, Cambridge, he went as Vice-Consul to Thessaloniki, and soon after became third Dragoman at Constantinople. When the Turkish capital moved to Ankara and the office of Dragoman was abolished, Helm went there as Second Secretary. He served there as Consul, and in 1930 was transferred to the Foreign Office, working in the Eastern Department.