Arumugam Manthiram (; born March 15, 1951) is an Indian-American materials scientist and engineer, best known for his identification of the polyanion class of lithium ion battery cathodes, understanding of how chemical instability limits the capacity of layered oxide cathodes, and technological advances in lithium sulfur batteries. He is a Cockrell Family Regents Chair in engineering, Director of the Texas Materials Institute, the Director of the Materials Science and Engineering Program at the University of Texas at Austin, and a former lecturer of Madurai Kamaraj University. Manthiram delivered the 2019 Nobel Lecture in Chemistry on behalf of Chemistry Laureate John B. Goodenough.