Johann Jakob Herzog (12 September 1805, Basel – 30 September 1882, Erlangen), German Protestant theologian, was born at Basel.
He studied at Basel and Berlin, and eventually (1854) settled at Erlangen as professor of church history.
His most noteworthy achievement was the publication of the Real-Encyklopädie für protestantische Theologie und Kirche (1853–1868, 22 vols.), of which he undertook a new edition with GL Plitt (1836–1880) around 1877, and after Plitt’s death with Albert Hauck (b. 1845). Hauck began the publication of the third edition in 1896 (completed in 22 vols., 1909).
His other works include Joh. Calvin (1843), Leben Oekolampadius (i 843), Die romanischen Waldenser (1853), Abriß der gesamten Kirchengeschichte (3 vols, 1876–1882, 2nd ed., G Koffmane, Leipzig, 1890–1892).