Bryan Grenfell is a population biologist, distinguished for his investigation into the spatiotemporal dynamics of pathogens and other populations. Bryan studies processes that occur in populations at different scales and how infections move through such groups of organisms. His work is crucial in helping to control disease in humans and animals.

His research is theoretical as well as based on large datasets, demonstrating how the density of a population and randomness interact to change the size and composition of populations. Alongside colleagues from the National University of Singapore, he studied measles in developed countries and is now extending his investigations to whooping cough and other infectious diseases.

Bryan is currently Professor of Ecology and Evolutionary Biology and Public Affairs at Princeton University in New Jersey. He was awarded the T. H. Huxley Medal from Imperial College London in 1991, and the Scientific Medal of the Zoological Society of London in 1995.