Professor of Statistical Epidemiology at Imperial College London, Christl Donnelly is one of the world’s foremost statistical epidemiologists working on infectious diseases. Her research has been instrumental in turning mathematical modelling from a theoretical tool for exploring transmission dynamics into an essential tool in the armoury of governments and public health agencies responding to emerging epidemics. The scientific impact of her research has been to improve dramatically the statistical robustness of mathematical modelling and hence the reliability of conclusions drawn from models – a major reason for their increasing adoption as tools to inform and influence public health policy-making.