After serving as Director of the Department of Maternal, Child and Adolescent Health, WHO Geneva, Anthony Costello returned to University College London in 2018 as Professor of Global Health and Sustainable Development. Trained in paediatrics, he is a founder and principal investigator of the international Lancet Countdown for Climate Action and Health since 2016, and senior adviser to the Children in All Policies 2030 programme supported by WHO, UNICEF and the Lancet.

For 30 years his research focused on health and social interventions to reduce maternal and newborn mortality, and latterly to improve nutrition and diabetes, in poor rural populations.His multiple, large scale population studies helped to change WHO policy. He helped to build partnership research institutions in Bangladesh, India, Malawi and Nepal. He received the James Spence medal of the Royal College of Paediatrics and Child Health in 2011, and a BMJ Lifetime Achievement Award in 2019.