Churchill served as a judge for the Wellcome Photography Prize 2021, one of the world's leading prizes for photography at the intersection of health, science and medicine. The prize received more than 10,000 submissions from 110 countries. Churchill sat on an eight-person panel chaired by Sir Jeremy Farrar, Director of Wellcome, alongside Brett Rogers OBE (Director of The Photographers' Gallery), Azu Nwagbogu (Founder of African Artists' Foundation and LagosPhoto Festival), and other leading figures from photography, medicine and science. The 2021 prize covered three categories: Managing Mental Health, Fighting Infections, and Health in a Heating World.