Drew Weissman (born September 7, 1959) is an American physician and immunologist known for his contributions to RNA biology. Weissman is the inaugural Roberts Family Professor in Vaccine Research, director of the Penn Institute for RNA Innovation, and professor of medicine at the Perelman School of Medicine at the University of Pennsylvania (Penn). Weissman's work underlies the development of mRNA vaccines, the best known of which are those for COVID-19 produced by BioNTech/Pfizer and Moderna. With biochemist Katalin Karikó, Weissman received the Nobel Prize in Physiology or Medicine in 2023 "for their discoveries concerning nucleoside base modifications that enabled the development of effective mRNA vaccines against COVID-19". Weissman has been a recipient and co-recipient of numerous awards, also including the prestigious Lasker–DeBakey Clinical Medical Research Award. In 2022, he was elected to the National Academy of Medicine and the American Academy of Arts and Sciences.