Frederick W. Alt is an American geneticist. He is a member of the Immunology section of the National Academy of Sciences and a Charles A. Janeway Professor of Pediatrics, and Professor of Genetics at Harvard Medical School.He is the Director of the Program in Cellular and Molecular Medicine at the Boston Children's Hospital. He is a Howard Hughes Medical Institute investigator since 1987.He received a Ph.D. in Biology from Stanford University in 1977, under the research direction of Robert Schimke, followed by postdoctoral work in David Baltimore's laboratory at MIT. From 1982-91 he was on the faculty at Columbia University and then moved to Harvard Medical School.He received Rosenstiel Award in 2014 for his pioneering work in elucidating the mechanisms of genome rearrangements in immune and cancer cells.