Nicolas Michaelovich Zernov (9 October 1898 [O.S. 21 September] - 25 August 1980) (Russian: Никола́й Миха́йлович Зёрнов) was a Christian Russian émigré who settled in Britain, and taught theology at Oxford University. He wrote many books about the Orthodox Church, and about Christianity in Russia, of which the best known is The Russian Religious Renaissance of the Twentieth Century (1963). He worked continuously for the unity of Christians, and from 1935 to 1947 was secretary of the ecumenical Fellowship of Saint Alban and Saint Sergius, which he helped to found in 1928.