Geoffrey Lilley Smith (born 1955) FRS FMedSci FRSB is a British virologist and medical research authority in the area of Vaccinia virus and the family of Poxviruses.
Since 1 October 2011 he is Head of the Department of Pathology at the University of Cambridge and a Principal Research Fellow of the Wellcome Trust.
Before that, he was Head of the Department of Virology at Imperial College London.