The Icahn School of Medicine at Mount Sinai (ISMMS), formerly the Mount Sinai School of Medicine (MSSM), is an American medical school in the New York City borough of Manhattan in the state of New York. Chartered by Mount Sinai Hospital in 1963, the ISMMS is one of the foremost medical schools in the United States, ranking 20th in research according to U.S. News & World Report, 18th in NIH funding among U.S Medical Schools (2014),and 3rd in NIH funding per primary investigator.

ISMMS and the Mount Sinai Hospital occupy a four-block area adjacent to Central Park on the Upper East Side of Manhattan, with architecture designed by I. M. Pei. ISMMS and Mount Sinai Hospital make up the Mount Sinai Medical Center, of which Kenneth L. Davis, MD, is the president and CEO. Dennis Charney, MD, the current Dean of the School of Medicine, became the Dean of Research at Mount Sinai School of Medicine in 2004, later becoming the Dean for Academic and Scientific Affairs, finally succeeding Kenneth L. Davis as Dean of the school in 2007.

In 2012–13, the Mount Sinai Medical Center was recognized on the U.S. News & World Report "Best Hospitals Honor Roll", ranking 14th among the approximately 5,000 hospitals in the US with 11 nationally ranked specialties including cancer, geriatrics, gastroenterology, cardiology and heart surgery, otolaryngology, rehabilitation, diabetes and endocrinology, neurology and neurosurgery, gynecology, urology, and kidney disorders.