Henry N. Chapman FRS is a British physicist and the founding director of the Center for Free-Electron Laser Science at the German Electron Synchrotron (DESY). He has made numerous contribution to the field of x-ray coherent diffraction imaging and is a pioneer of the diffraction before destruction technique that allows to analyze biological samples with intense, ultrafast x-ray light, such as Photosystem II, a key element in photosynthesis. He is married to the Slovenian physicist Saša Bajt.