Graham Roger Serjeant CMG (born 1938) is a British medical researcher who studied sickle-cell disease in Jamaica, setting up screening programmes and long-term cohort studies. He was Director of the MRC Epidemiology Research Unit at the University of the West Indies and remains chairman of the Sickle Cell Trust (Jamaica). He is author or co-author of three books and over 140 publications on sickle-cell disease. His work has addressed the variability of sickle-cell disease with special emphasis on developing low-cost models of management suitable to countries with large numbers of patients and limited resources.