 Knatchbull-Hugessen was educated at Eton and Magdalen College, Oxford, where he was President of the Oxford Union.In 1857 Knatchbull-Hugessen was elected Member of Parliament for Sandwich, a seat he would hold until 1880.He served as a Lord of the Treasury under Lord Palmerston from 1859 to 1860, as Under-Secretary of State for Home Affairs under Lord Russell in 1866 and under Gladstone from 1868 to 1871 and as Under-Secretary of State for the Colonies under Gladstone from 1871 to 1874.