F. Mason Sones Jr. (1918-1985) was a pioneering cardiologist whose groundbreaking work revolutionized the field of cardiology. His accidental discovery of coronary angiography in 1958 at the Cleveland Clinic provided physicians with the first clear visualization of coronary arteries in living patients, paving the way for the development of coronary artery bypass surgery and interventional cardiology. This review article explores F. Mason Sones Jr.'s life and career, and his lasting impact on the field of cardiology. Born in Noxapater, MS, in 1918, F. Mason Sones Jr.attended Western Maryland College (Westminster, MD) and the University of Maryland School of Medicine (Baltimore, MD) before completing his internship and residency at the University Hospital (Baltimore, MD) and Henry Ford Hospital (Detroit, MI), respectively. After serving in the U.S. Army Air Corps during World War II, F. Mason Sones Jr.joined the Cleveland Clinic (Cleveland, OH), in 1950, as the head of pediatric cardiology, where he combined his expertise in cardiac catheterization with his interest in congenital heart disease. F. Mason Sones Jr.'s serendipitous discovery of coronary angiography occurred during a routine cardiac catheterization procedure when he inadvertently injected contrast dye directly into the right coronary artery. Realizing that smaller amounts of dye could safely opacify the coronary arteries, F. Mason Sones Jr. refined and standardized the technique of selective coronary angiography, collaborating with engineers to improve X-ray imaging and establishing protocols that remain the standard of care today. F. Mason Sones Jr.'s work provided the foundation for the development of coronary artery bypass surgery by Dr. René Favaloro and the birth of interventional cardiology, as pioneered by Dr. Andreas Gruentzig. As the director of cardiovascular disease at the Cleveland Clinic (1966-1975), F. Mason Sones Jr. mentored and inspired a generation of cardiologists, cementing his legacy as a visionary leader in the field. Throughout his career, F. Mason Sones Jr. received numerous awards and honors, including the American Medical Association's Scientific Achievement Award and the Gairdner Foundation International Award. He co-founded and served as the first president of the Society for Cardiac Angiography (now SCAI), an organization dedicated to advancing the field of interventional cardiology. This review article pays tribute to F. Mason Sones Jr.'s enduring contributions to the field of cardiology, highlighting his role as a pioneer, innovator, and mentor. His legacy continues to inspire and guide generations of cardiologists in their pursuit of improving patient care and pushing the boundaries of cardiovascular medicine.