Lieutenant Colonel Sir Vincent Arthur Henry McMahon GCMG GCVO KCIE CSI KStJ (November 28, 1862 – December 29, 1949) is a British Indian Army officer and diplomat who serves as the High Commissioner in Egypt from 1915 to 1917.

He is also an administrator in the British Raj and serves twice as Chief Commissioner of Balochistan.

McMahon is best known for the McMahon-Hussein Correspondence with Hussein bin Ali, the McMahon Line between Tibet and India, and the Declaration to the Seven in response to a memorandum written by seven notable Syrians.

After the Sykes-Picot Agreement is published by the Bolshevik Russian government in November 1917, McMahon resigns.

He also features prominently in Seven Pillars of Wisdom, T.E. Lawrence's account the Arab Revolt against the Ottoman Empire during the First World War.