General Sir Charles Whittingham Horsley Douglas GCB, ADC (17 July 1850 – 25 October 1914) was a British Army officer who served in the Second Anglo-Afghan War, the First Boer War, the Suakin Expedition, the Second Boer War and World War I. He was Chief of the Imperial General Staff during the first three months of World War I but died from strain and overwork without having any meaningful influence on the outcome of the War.