diplomat who represented Great Britain in the so-called Sykes-Picot (Sykes-Picot Agreement) negotiations (1915–16) concerning the dismemberment of the Ottoman Empire after World War I.

Sykes served in the South African (Boer) War (1899–1902) and was personal secretary (1904–05) to George Wyndham, British chief secretary in Ireland. After traveling in Asiatic Turkey for several years, he wrote vivid accounts of his journeys, including Through Five Turkish Provinces (1900) and The Caliph's Last Heritage (1915). He was elected to Parliament in 1911.

Early in World War I, the British government employed Sykes on diplomatic missions in the Balkans and Turkey. He then was chief British representative in the negotiations with France and tsarist Russia that resulted in a secret accord known as the Sykes-Picot Agreement (May 1916). Under its terms, Syria and Iraq were to be divided into spheres of French and British influence and even direct administration; Palestine was to be subject to international control. When made public by the Russian Revolutionary government in 1917, these arrangements infuriated the Arabs, who had been led to expect postwar independence. Until the end of the war Sykes undertook Middle Eastern missions for the British Foreign Office.