Andrew Tatem is Professor of Spatial Demography and Epidemiology at the University of Southampton and is the Director of WorldPop (www.worldpop.org), leading a group of 40 researchers and data scientists. He is interested in how populations, their characteristics and their dynamics can be mapped at high resolution across low and middle-income countries. His research has led to pioneering approaches to the use and integration of satellite, survey, cell phone and census data to map the distributions and movement patterns of vulnerable populations for disease, disaster and development applications. He runs international collaborations with national governments, UN agencies and data providers, and leads multiple research and operational projects funded by the Bill and Melinda Gates Foundation, Wellcome Trust, World Bank, GAVI, UK Foreign Commonwealth and Development Office and others.