Mark G. Thomas (born 5 June 1964 on Kingston-upon-Thames, Surrey, England) is a human evolutionary geneticist, Professor of Evolutionary Genetics at the Research Department of Genetics, Evolution and Environment at University College London since 2009. Prior to this, he was Cancer Research Campaign Postdoctoral Research Fellow at King's College London and then Wellcome Trust postdoctoral researcher in the department of Biological Anthropology at the University of Cambridge. He has acted as Editor-in-chief of the journal Annals of Human Genetics from 2015 to 2019 and Oct 2020 to Jan 2021.