Karl Friedrich Otto von Gerlach (12 April 1801 – 24 October 1849) was a German theologian and pastor from Berlin. He was the youngest of five children of (1757–1813), first Lord Mayor of Berlin, and (1795–1877), and brother of Ernst Ludwig von Gerlach (1795–1877) and Ludwig Friedrich Leopold von Gerlach (1790–1861). Otto von Gerlach first studied law, then theology in Berlin, Heidelberg and Göttingen. He was influenced by the Great Awakening movement and was a member of the of (1796–1882).