Sir Clements Robert Markham KCB FRS FRSGS (20 July 1830 – 30 January 1916) was an English geographer, explorer and writer. He was secretary of the Royal Geographical Society (RGS) between 1863 and 1888, and later served as the Society's president for a further 12 years. In the latter capacity he was mainly responsible for organising the British National Antarctic Expedition of 1901–1904, and for launching the polar career of Robert Falcon Scott.