Hartmut Lehmann (born April 29, 1936) is a German historian of modern history who specializes in religious and social history. He is known for his research on Pietism, secularization, religion and nationalism, transatlantic studies and Martin Luther. He was the founding director of the German Historical Institute Washington DC and was a director of the Max Planck Institute for History.[1] He is an emeritus honorary professor at Kiel University and the University of Göttingen.