Marlene Belfort (born 1945) is an American biochemist. She is Professor at the Wadsworth Center at the New York State Department of Health. She received her Ph.D. from the University of California, Irvine in 1972 and did postdoctoral research at the Hebrew University, Jerusalem. She was involved in the discovery of self-splicing introns in bacteriophage DNA, and continues to do research in the area. She was elected a Fellow of the American Academy of Arts and Sciences in 1994 and was admitted to the United States National Academy of Sciences in 1999.