Sir Sidney Lee (5 December 1859 – 3 March 1926) was an English biographer and critic. He was born Solomon Lazarus Lee at 12 Keppel Street, Bloomsbury, London and educated at the City of London School and at Balliol College, Oxford, where he graduated in modern history in 1882. In the next year he became assistant-editor of the Dictionary of National Biography. In 1890 he became joint editor, and on the retirement of Sir Leslie Stephen in 1891 succeeded him as editor.