S Ramaseshan is distinguished Professor Emeritus at the Raman Research Institute, Bangalore, India. He is a distinguished crystallographer and a specialist in Anomalous scattering techniques for solving the phase problems in X-ray and Neutron Crystallography. He collaborated with Dorothy Hodgkin in her insulin work using Anomalous techniques. He has been the vice president, International Union of Crystallographers; Chairman, National Committee of Crystallography, India; and Director, Indian Institute of Science, Bangalore, India.