Mark E. Josephson (1943-2017) was an American cardiologist and writer, who was in the 1970s one of the American pioneers of the medical cardiology subspecialty of cardiac electrophysiology. His book titled Clinical Cardiac Electrophysiology: Techniques and Interpretations is widely acknowledged as the definitive treatment of the discipline. He was the Herman Dana Professor of Medicine at Harvard Medical School and the director of the Harvard-Thorndike Electrophysiology Institute and Arrhythmia Service. He was also until 2016 the chief of cardiology at Harvard University's Beth Israel Deaconess Medical Center in Boston.