Mark G. Alford (born 3 July 1962) is a theoretical physicist and former chair (2012-2022) of the Department of Physics at Washington University in St. Louis. He researches dense matter inside neutron stars.
Alford received his bachelor's degree with first-class honors from Oxford in 1984 and his master's and doctoral degrees from Harvard in 1988 and 1990, respectively, under the supervision of Sidney Coleman. Afterwards he held postdoctoral positions at the University of California, Santa Barbara Institute for Theoretical Physics (now the Kavli Institute), Cornell's Laboratory of Nuclear Studies, the Institute for Advanced Study, and the MIT Center for Theoretical Physics. He became a lecturer at the University of Glasgow in 2000, before becoming professor at Washington University in 2003. He is a fellow of the American Physical Society.