Sir Charles William Chadwick Oman KBE (12 January 1860 – 23 June 1946) was a British military historian. His reconstructions of medieval battles from the fragmentary and distorted accounts left by chroniclers were pioneering. Occasionally his interpretations have been challenged, especially his widely copied thesis that British troops defeated their Napoleonic opponents by firepower alone. Paddy Griffith, among modern historians, claims that the British infantry's discipline and willingness to attack were equally important.
Oman was born in Muzaffarpur district, India, the son of a British planter, and was educated at Winchester College and at Oxford University, where he studied under William Stubbs. In 1881 he was elected to a Prize Fellowship at All Souls College, where he remained for the rest of his academic career. He was elected the Chichele Professor of Modern History at Oxford in 1905, in succession to Montagu Burrows. He was also elected to the FBA that year, and served as President of the Royal Historical Society (1917–1921), the Numismatic Society and the Royal Archaeological Institute.
Oman's academic career was interrupted by the First World War, during which he was employed by the government's Press Bureau and the Foreign Office.
Oman was the Conservative Member of Parliament for the University of Oxford constituency from 1919 to 1935, and was knighted in 1920.